G.R. No. 135199 . July 5, 2001.
SPOUSES CRISOSTOMO MAGAT and EDITHA A. MAGAT, petitioners, vs. SPOUSES ALBERT M. DELIZO and CARMINA H. DELIZO, represented by their Attorney-in-fact, EVANGELINE A. HERNANDEZ, respondents.

FACTS

On November 9, 1993, respondent spouses Albert and Carmina Delizo filed a complaint for specific performance against Slim Realty and Construction Inc. (SLIM) and Simon Lim before the Regional Trial Court (Civil Case No. Q-93-18214). The complaint alleged that SLIM sold them a property, and upon payment of an initial amount, SLIM would deliver the property and its title. Respondents claimed they had almost fully paid the purchase price, with only a small balance remaining, but SLIM failed to deliver the title and had instead mortgaged the property. On April 7, 1994, the parties entered into a Compromise Agreement wherein respondents would pay the balance and SLIM would deliver the title within 45 days. The trial court approved this agreement. The judgment was executed: a notice of levy was issued, the property was sold at auction to respondents, a final deed of sale was issued, and a new title (TCT No. N-163425) was issued in their favor on August 2, 1996. Subsequently, on October 1, 1997, petitioners Crisostomo and Editha Magat filed a “Motion to Intervene and Urgent Motion to Hold Writ of Possession,” claiming they had purchased the same property from SLIM on March 21, 1996. They later filed a “Motion to Declare the Proceeding Null and Void,” arguing the trial court lacked jurisdiction because the case involved a subdivision lot, which falls under the exclusive jurisdiction of the Housing and Land Use Regulatory Board (HLURB) under P.D. 1344. The trial court agreed with petitioners and issued an Order on October 24, 1997, dismissing the case and declaring all proceedings null and void for lack of jurisdiction. Respondents challenged this order. The Court of Appeals granted respondents’ petition, set aside the trial court’s order, and ruled the trial court had jurisdiction. Petitioners appealed to the Supreme Court.

ISSUE

1. Whether the trial court had jurisdiction over the complaint for specific performance or if it was exclusively vested in the HLURB.
2. Whether the trial court properly entertained the petitioners’ motion for intervention filed after the judgment based on the compromise agreement had become final and executory and had been substantially executed.

RULING

The Supreme Court AFFIRMED the Decision of the Court of Appeals.
1. On jurisdiction: The Court held that the trial court had jurisdiction. The records did not show the property was a subdivision lot or condominium unit subject to HLURB’s exclusive jurisdiction under P.D. 1344. The complaint referred only to “a piece of real estate,” and the deed of sale described it as a “house and lot.” The controversy was a simple sale of a house and lot on installment, properly cognizable by the regular courts.
2. On intervention: The Court ruled the motion for intervention was improperly filed and should not have been entertained. Under the Rules of Court, a motion to intervene must be filed before the rendition of judgment by the trial court. Here, the motion was filed after the judgment based on the compromise agreement had become final and executory and had been substantially executed (with a new title already issued to respondents). Allowing intervention at that late stage would unduly delay and prejudice the adjudication of the original parties’ rights. The intervenors’ rights could be fully protected in a separate proceeding.
Furthermore, a compromise agreement approved by the court has the force of res judicata and is immediately executory and not appealable, except on grounds of vices of consent or forgery. It was the ministerial duty of the trial court to enforce the judgment. Any grievance by the petitioners should be ventilated in a separate action.