Petitioners seek a reversal of the decision of respondent court dated December 7, 1990 and its resolution dated May 6, 1991, dismissing their petition for certiorari and prohibition to set aside the resolution dated August 8, 1989 of the Regional Trial Court of Lingayen, Pangasinan, Branch 37, which reconsidered and set aside its previous resolution dated May 25, 1989, dismissing private respondents' re-amended complaint on the ground of lack of jurisdiction.

The antecedent facts are as follows:

On August 16, 1976, spouses Braulio and Aquilina Abalos filed before the Regional Trial Court of Lingayen, Pangasinan, Branch 38, an application for registration of title over Lot No. 60052 and three-fourths (3/4) pro-indiviso of Lot No. 8459, situated in barangay Baay, Lingayen and under Cad-373-D of the Lingayen Cadastre (docketed as Land Registration Case No. N­-3405, Record No. N-49833), with the remaining one-fourth (1/4) pro-indiviso portion thereof belonging to Roman Soriano.

On February 17, 1977, the trial court, sitting as a land registration court, issued an order of general default against the whole world except the Director of Lands and Roman Soriano who had filed their respective oppositions to the application. In his opposition, oppositor Soriano alleged that the two lots mentioned in the application had in fact not yet been divided and therefore, he is a co-owner to the extent of one-seventh (1/7) pro-indiviso of the combined areas of Lot Nos. 60052 and 8459 and not only one-fourth (1/4) of Lot No. 8459.

In the course of the hearing, it was established that the lots in question were originally owned by Adriano Soriano who was in continuous, open and adverse possession in the concept of an owner until his death in 1947. Thereafter, Adriano's heirs executed a deed of extrajudicial partition stating that the property was inherited by seven of his nine children, namely: Candido, Lourdes, the heirs of Dionesia, Roman, Francisca, Librada and Elcocadio. The two other children were given other properties.

The above-named heirs likewise decided to subdivide the property into the northern and southern portions which were then separately declared for taxation purposes, i.e., tax declaration No. 5065 for the northern and tax declaration No. 5066 for the southern portion. The northern portion went to Candido, Lourdes and the heirs of Dionesia while the southern portion was declared in the names of oppositor Roman, Francisca, Librada and Elcocadio or one-fourth (1/4) pro-indiviso shares each.

In 1971, Candido, Lourdes and the heirs of Dionesia sold their shares in the northern portion to petitioner spouses Abalos. In the same year, Lourdes, Librada and Francisca sold their three-fourths (3/4) shares of the southern portion also to petitioner spouses. Respondent Soriano raised no objections in regard to the aforementioned sale of the properties.

Based on the above findings, the land registration court in its decision dated June 27, 1983 granted the application for registration of spouses Abalos. The court specifically held therein that "(t)he deeds of conveyances executed by the former owners of the property in question in favor of the herein applicants, bearing all the legal formalities under the safeguard of a notarial certificate and there being no showing that the contracts of sale entered into by the parties were fraudulent, fictitious and simulated, it is presumed that the recitals thereof are true and correct and a high degree of proof is necessary to overcome this legal presumption" (Rollo, p. 75). The dispositive portion of the decision reads:

"Accordingly, pursuant to the Land Registration Law, known as Act 496, as amended, this Court hereby confirms the title of the herein applicants over the parcel of land denominated as Lot No. 60052 and over the three-fourth (3/4) pro-indiviso portion of the land mentioned as Lot No. 8459, described and bounded in Plan AP-1-0028 marked as Exhibit A and series and the technical description (Exhibits B and C), and therefore adjudicates the said properties in the name of the herein applicants, Braulio R. Abalos and Aquilina Soriano, of legal ages, Filipinos and residents of Barangay Baay, Lingayen, Pangasinan, Philippines, as their conjugal property.

"This Court also confirms the title of the herein private oppositor over the one-fourth (1/4) pro-indiviso portion of Lot No. 8459 described and bounded in Plan AP-1-00228 (Exhibit A and series) and the technical description (Exh. B) and hereby adjudicates the said property in the name of Roman Soriano II, of legal age, Filipino, married to Beatriz Castro, and a resident of Barangay Baay, Lingayen, Pangasinan, Philippines, as his exclusive property. "The opposition of the Republic of the Philippines is hereby dismissed for lack of basis.

x x x

"SO ORDERED." (Rollo, p. 76)

Roman Soriano appealed the above decision to the then Intermediate Court of Appeals (docketed as AC-G.R. C.V. No. 02077).

In its decision dated January 31, 1985 (Rollo, pp. 78-88), the appellate court affirmed the decision of the trial court. On the issue of whether or not the lower court, sitting as a land registration court, has jurisdiction to rule on the validity of deeds of sale, the appellate court cited Franco v. Monte de Piedad and Savings Bank (7 SCRA 660 [1963]) which held that the general rule that a land registration court has no power to decide matters which are properly litigable in ordinary civil actions admits of exceptions as when the parties have acquiesced in submitting said matters for determination in the land registration proceedings and the parties are afforded full opportunity to present their respective sides and evidence. It also cited Zuñiga v. Court of Appeals (95 SCRA 740 [1980]), which held that a land registration court may not be denied the necessary powers to exercise such jurisdiction which shall make it effective and this includes the power to determine the validity of deeds of conveyances. As the appellate court concluded: "x x x where the issue of the genuineness of a document is presented in a land registration case, the CFI (now RTC) sitting as a land registration court should not in any manner hesitate to determine the conflicting claims of the parties; otherwise, that would practically reduce said court to impotence to determine questions of facts, since claims on such a disputed land more often than not are based on documents of title, and it is only natural that the issue of genuineness would be raised against said document." (Rollo, pp. 86-87)

Brought before this Court on a petition for review on certiorari (docketed as GR No. 70842), Soriano's petition was likewise denied for lack of merit in a Resolution dated November 11, 1985 and entry of judgment was entered on December 16, 1985 (Rollo, pp. 90-91)).

It appears that on July 15, 1983, or a day after the promulgation of the trial court's decision granting the application of petitioners in the land registration case, oppositor Soriano, together with Elcocadio and Librada Soriano filed a complaint against spouses Abalos for the annulment of document and/or redemption, ownership and damages (docketed as Civil Case No. 15958) before the Regional Trial Court of Pangasinan, Branch 37.

The spouses Abalos filed a motion to dismiss the complaint (CC No. 15958) on the grounds of res judicata, pendency of another action, lack of cause of action, laches, misjoinder of parties and lack of jurisdiction. The trial court (branch 37) denied the motion and instead directed the spouses to file their Answer, which they did on January 30, 1984.

Upon the demise of oppositor Soriano, his counsel in Civil Case No. 15958 filed an amended complaint to substitute his heirs as party-plaintiffs. On March 14, 1988, the heirs of Roman Soriano filed another motion for leave to admit re-amended complaint which sought to implead Juanito Ulanday, one of petitioners herein, as additional party-defendant for having allegedly purchased part of the disputed property from the spouses Abalos. Petitioner spouses opposed the admission of the re-amended complaint. Subsequently, the heirs of Soriano filed another re-amended complaint dated October 21, 1988 in lieu of the opposed re-amended complaint.

On motion of the spouses Abalos, the trial court issued a resolution dated May 25, 1989 granting the motion to dismiss the re-amended complaint on the ground that the re-amended complaint altered the original cause of action.

Respondent heirs of Soriano moved for a reconsideration of the said resolution and on August 8, 1989, the trial court issued another resolution setting aside its May 25, 1989 resolution and ordered the spouses Abalos to file their answer to the re-amended complaint (Rollo, p. 142). Petitioner spouses' "Motion for, and Opposition to, Motion for Reconsideration" having been filed late, the trial court resolved to deny the same for being moot and academic (Rollo, p. 152).

Petitioners filed a petition for certiorari and prohibition before the respondent court alleging grave abuse of discretion having been committed by the trial court in not dismissing the re-amended complaint. Petitioners contend that the refusal of the trial court to dismiss respondent's re-amended complaint amounted to lack of jurisdiction because it ignored the decisions of the land registration court, the Court of Agrarian Relations, the Court of Appeals and as well as that of this Court in the previous land registration case involving the same parties, the same subject matter and the same issues.

Respondent court disagreed with the petitioners and dismissed the petition. It ruled that the lower court, acting as a land registration court, exercises limited jurisdiction. Therefore, it cannot pass upon questions regarding the validity of contracts affecting the disputed property. Accordingly, a land registration court having limited jurisdiction may not resolve an issue involving the validity of the deed of sale which is ordinarily cognizable by a court of general jurisdiction. Concluding, respondent court held that the trial court committed no error when it refused to adhere to the rule on res judicata which requires that the resolution of the issue in the prior case should have been made by a court of competent jurisdiction.

We reverse.

Respondent court is in error to rule that the trial court, sitting as a land registration court, is without authority to determine conflicting claims of ownership over the land sought to be registered. True, a land registration court exercises special and limited jurisdiction. But this is not without exception.

From an otherwise rigid rule outlining the jurisdiction of a land registration court being limited in character, deviations have been sanctioned under the following circumstances where: (1) the parties agreed or have acquiesced in submitting the aforesaid issues for determination by the court in the registration proceedings; (2) the parties were accorded full opportunity in presenting their respective arguments of the issues litigated and of the evidence in support thereof; and (3) the court has already considered the evidence on record and is convinced that the same is sufficient and adequate for rendering a decision upon the issues controverted. (Manalo v. Mariano, 69 SCRA 80 [1976]; Zuñiga v. Court of Appeals, 95 SCRA 740 [1980], citing Aglipay v. De los Reyes, 107 Phil 331 [1960]; Florentino v. Encarnacion, Jr., 79 SCRA 192 [1977]; Franco v. Monte de Piedad, 117 Phil. 672 [1963]; See also Republic v. Neri, et al., G. R. No. 57475, September 14, 1992)

Here, the issue of ownership was fully ventilated before the land registration court with both of the parties presenting oral and documentary evidence to sustain their respective claims. It was a full-dress trial on the merits of the applicants' (herein petitioners) claim over the parcels of land with the then oppositor, Roman Soriano, having been accorded every opportunity to refute the same. As found by the land registration court: the Abalos spouses obtained ownership over the land in controversy through the deeds of sale which were evidenced by Exh. "N", executed on September 28, 1971 by Elcocadio, Librada and Francisca Soriano over their three‑fourths (3/4) share on Lot No. 8459; Exh. '"O", executed on April 9, 1971 by Candido Soriano over his one-third (1/3) share; Exh. "P", executed on September 27, 1971 by the Quinotoses over their one-third (1/3) share; Exh. "Q", executed on September 21, 1971 by Lourdes Soriano over her one-third (1/3) share.

Indeed, Soriano even offered to sell his shares in the property to petitioners spouses but the latter found the conditions so onerous that the transaction failed to materialize.

In land registration proceedings, it is expected of the applicant to adduce evidence, testimonial and documentary, and for the oppositor to adduce proof of equal, if not more, evidentiary weight to defeat the claim of ownership. The purpose of the applicant is to prove that he has absolute or registerable title over the property applied for. The oppositor, on the other hand, claims a right totally adverse to the applicant. The land registration court must decide as to who has a better right and determine the authenticity of the documents relied upon by the party claimants.

Given the highly contentious nature of a land registration proceeding, in rem and binding on the whole world, the claim as to whether or not the land applied for is registerable or not necessarily entails a resolution on the question of the validity of the document upon which the applicant anchors his claim of dominion or ownership. The question is not foreign, but is material and germane, to the crux of the controversy, i. e., whether or not the applicant possesses registerable title in the realty claimed. If a land registration court is not allowed to rule on the question of controverted ownership when the parties themselves acquiesced in the resolution thereof, how could said court be expected to render a decision on applications for land registration? The claim of ownership in land registration cases is more often evidenced by documents. Otherwise, how could an applicant and/or oppositor prove their respective claims of ownership?

In Manalo v. Mariano (supra), this Court had occasion to pass upon a similar issue -- whether the trial court can entertain an action for annulment of a partition agreement on the ground of fraud although its validity had already been upheld by Branch VII of the same court in a land registration case. In said case, the trial court denied the motion to dismiss based on bar by prior judgment in the land registration case. Reversing the trial court, we held:

"The lower court in its orders dated March 10 and July 17, 1971 denied the motion to dismiss. It ruled that the decision in the land registration case did not constitute res judicata as to the validity of the 'Kasulatan' in question because Severino Manalo did not testify in the land registration case regarding its execution and, moreover, the lower court, as a land registration court with limited jurisdiction, allegedly could not resolve that issue.

"On August 5, 1971 Demetrio Manalo filed the instant petition for certiorari and prohibition. The issue is whether the action for the annulment of the partition agreement is barred by res judicata.

"We hold that such action is barred by the prior judgment in the land registration case. The decision in a land registration proceeding, which is proceeding in rem, is conclusive upon the title to the land and is binding on the whole world (Sec. 49 [a], Rule 39, Rules of Court).

"In the instant case, the decision in Land Registration Case No. N-6347 may also be regarded as a judgment in personam against Severino Manalo. He was the oppositor in that case. He presented evidence in support of his opposition particularly with reference to the supposed nullity of the 1960 partition agreement. He asked that the contested lots be registered in his name. The lower court ruled against his contentions and sustained the application of Demetrio Manalo.

"The lower court's decision is conclusive against Severino Manalo. It has all the elements of res judicata vis-a-vis Civil Case No. 13708: (a) a final judgment, (b) a court with jurisdiction over the res and the parties, (c) a judgment on the merits, and (d) identity of the parties, subject-matter and cause of action.

"Severino Manalo's contention that the lower court, as a land registration court, had no jurisdiction to pass upon the validity of the 1960 partition agreement is not well-taken. The Court of First Instance (now RTC) is a court of 'general original jurisdiction' 'invested with power to take cognizance of all kinds of cases': civil cases, criminal cases, special proceedings, land registration, guardianship, naturalization, admiralty and insolvency cases x x x.

"Whether a particular matter should be resolved by the Court of First Instance (now RTC) in the exercise of its general jurisdiction or of its limited jurisdiction as a special court (probate, land registration, etc.) is in reality not a jurisdictional question. It is in essence a procedural question involving a mode of practice 'which may be waived' (Cunanan v. Amparo, 80 Phil. 227, 232; Cf. Reyes v. Diaz, 73 Phil. 484 re jurisdiction over the issue).

"Thus, although a probate court may not decide a question of title, yet if the parties submit that question to the probate court and the interests of third parties are not impaired, the probate court may have jurisdiction to decide that issue (Pascual v. Pascual, 73 Phil. 56).

"Generally, an issue properly litigable in an ordinary civil action under the general jurisdiction of the Court of First Instance (RTC) should not be resolved in a land registration proceeding. But since in this jurisdiction the Court of First Instance (RTC) also functions as a land registration court, if the parties acquiesced in submitting that issue for determination in the land registration proceeding and they were given full opportunity to present their respective sides and their evidence, the land registration court would have jurisdiction to pass upon that issue (citing cases).

"In this case Severino Manalo himself invoked the court's jurisdiction by praying that the deed of partition be 'declared null and void' and that the disputed lands be registered in his name. He and Demetrio Manalo in effect agreed to submit the issue for adjudication by the lower court, sitting as a land registration court. That was merely a matter of practice or procedure. It did not mean that the parties asked the lower court to exercise a jurisdiction which it did not possess.

"In such a situation, the rule is that a party cannot invoke the court's jurisdiction to secure affirmative relief against his opponent and after failing to obtain such relief, repudiate or question that same jurisdiction (Dean v. Dean, 86 ALR 79; Tijam v. Sibonghanoy, 23 SCRA 29 [1968])."

The circumstances obtaining in the above-cited case are on all fours with the instant petition. As such, the pronouncement made therein finds full application in the case at bar.

Having disposed of the above issue, we now find petitioner's prayer to dismiss Civil Case No. 15958 on the ground of res judicata impressed with merit.

The principle of res judicata embraces two concepts. Where as between the first case where the judgment is rendered and the second case where such judgment is invoked, there is identity of parties, subject matter and causes of action, the judgment on the merits in the first case constitutes an absolute bar to the subsequent action not only as to every matter which was offered and received to sustain or defeat the claim or demand, but also as to any other admissible matter which might have been offered for that purpose and to all matters that could have been adjudged in that case. This is what is called "bar by former judgment".

It is well-settled that for a prior judgment to constitute a bar to a subsequent action, (1) there must be a final judgment or order, (2) the court rendering the same must have jurisdiction over the subject matter and over the parties, (3) it must be a judgment on the merits and (4) there must be between the two cases, identity of the parties, subject matter and causes of action.

On the other hand, where the second action between the parties is upon a different claim or demand, the judgment in the first case operates as an estoppel only with regard to those issues directly controverted, upon the determination of which the judgment was rendered. This is the rule on "conclusiveness of judgment" (Sec. 49 [c], Rule 39; Tiongson v. Court of Appeals, 49 SCRA 429 [1973] and cases cited therein).

In the complaint filed by private respondents, it appears that respondents' cause of action is predicated upon the annulment of the deeds of sale and/or redemption or ownership of the disputed parcels of land. Whether it be for annulment or claim of ownership, the Court finds that respondents' action instituted before the trial court falls within the ambit of res judicata and should be dismissed.

Respondents' claim of nullity of the deeds of sale executed by Elcocadio, Francisca and Librada in favor of petitioner spouses before the RTC, Branch 37 of Lingayen was already raised and passed upon by the land registration court (RTC, Branch 38). In other words, it was the same defense advanced by private respondents in their effort to defeat petitioner spouses' claim of ownership in the land registration case which, unfortunately, was belied by the records therein. The judgment on the merits in the land registration case as affirmed by this Court in G. R. No. 70842, entitled Roman Soriano v. Intermediate Appellate Court, et al., constitutes an absolute bar to the subsequent action not only as to every matter which was offered and received to sustain or defeat the claim or demand, but also as to any other admissible matter which might have been offered for that purpose and to all matters that could have been adjudged in that case.

Neither can respondents Elcocadio and Librada Soriano find solace in the fact that by being not parties to the land registration case, they can now find legal personality to annul the alleged deed of sale executed by them in favor of petitioner spouses. The fact is, Elcocadio and Librada Soriano failed to oppose petitioner spouses' application for land registration. A land registration proceeding is an action in rem; it is binding on the whole world such that whoever failed to oppose an application, including the Republic, is bound by the order of general default. As a matter of fact, Elcocadio and Librada Soriano even testified before the land registration court assailing the validity of the aforesaid sale. This is more than enough constructive notice and they cannot, by the mere variance of action predicated upon (CC No. 15958), be allowed to again litigate what had already been adjudged.

Consequently, respondents are barred from assailing again the validity of the conveyances in Civil Case No. 15958 filed before Regional Trial Court, Branch 37, for the simple reason that the same has already been litigated and passed upon in the previous land registration case and affirmed by us. The disputed property could not have been registered in the name of petitioner spouses were it not found by the land registration court that petitioners were the real and legitimate owners thereof.

A party may be at liberty to vary his form of actions by bringing in new issues or arguments; but just the same, he cannot escape the application of the principle of res judicata nor can a party avoid an estoppel of a former judgment by bringing forward in a second action new or additional grounds in support of his case or arguments to sustain it, the facts remaining the same, at least where such additional matter could have been pleaded in the prior action (Filinvest Credit Corporation v. Intermediate Appellate Court, 207 SCRA 59 [1992]).

With regard to the issue of redemption raised by private respondents in its complaint below, suffice it to state that it was established in LRC No. N-3405 that at the time of the sale of Lot No. 60052 to petitioner spouses, said parcel of land has already been segregated from Lot No. 8459. Records disclose that Lot No. 60052 had been partitioned among Candido, Lourdes and the heirs of Dionesia who later declared their respective shares of one-third (1/3) each under separate tax declarations. No longer held pro-indiviso at the time the subject properties were sold to the petitioner spouses, the right of legal redemption accorded under Article 1620 of the Civil Code can no longer be availed of for it applies only if the co-ownership still exists. No legal redemption may be made where the subject property has been partitioned or an identified share thereof has been sold (Mendoza I v. Court of Appeals, 199 SCRA 778 [1991], citing Umengan v. Butucan, 117 Phil. 325; Caro v. Court of Appeals, 113 SCRA 10 [1982]).

WHEREFORE, the petition is GRANTED and the assailed decision of the respondent court is hereby REVERSED and SET ASIDE. The Regional Trial Court, Branch 37, of Lingayen, Pangasinan, is further ordered to dismiss Civil Case No. 15958 with costs against plaintiffs therein. Costs against private respondents in this instance.

SO ORDERED.

Feliciano, (Chairman), Davide, Jr., and Romero, JJ., concur.
Melo, J., no part.