The case is a petition for certiorari1 [Under Rule 65, 1964 Revised Rules of Court.] to set aside the resolution of the National Labor Relations Commission2 [In NLRC-NCR Case No. 00-01-00137-90. Putong, Com., ponente, Carale, Pres. Com. And Veloso, Com.] denying the appeal from the Labor Arbiter’s decision3 [Penned by Daniel C. Cueto.] ordering petitioner's reinstatement as security guard with full back wages, on the ground that it was issued with grave abuse of discretion.

The facts are as follows:

On January 5, 1989, respondent E & R security agency hired petitioner Chona P. Torres as a security guard.

On October 27, 1989, during a routinary meeting of the security guards of the agency assigned to the Philippine Aerospace Development Corporation, the issue of granting a P25.00 pay increase pursuant to Republic Act No. 6727 was taken up and questions were raised as to the date of implementation of the increase. Petitioner Chona P. Torres stood up and uttered aloud at the presiding officer: "BAKIT ANG SASABIHIN NINYO SA OPISINA AT DITO AY MAGKAIBA!" to which remark the presiding officer replied: "WALA NAMAN PAGKAKAIBA, DI BA?". The presiding officer also asked: "BAKIT AYAW MO DOON SA OPISINA?" Then petitioner shouted: "WALA NA AKONG TIWALA SA INYO AT SA AGENCY KASI SINUNGALING KAYO. EH, KUNG LALAKI LANG AKO, BAKA KUNG ANO PA ANG NAGAWA KO SA INYO NGAYON!"4 [Original Record, p. 18.]

On October 27, 1989, respondent agency sent petitioner a letter which states:

On October 30, 1989, petitioner filed with the National Labor Relations Commission, Arbitration Branch, against respondent E & R Security Agency, Inc. a complaint for illegal suspension and violation of R. A. No. 6727, and for having been required to sign on a blank payroll.6 [Original Record, p. 21.]

On November 10, 1989, petitioner received a letter from the agency informing her that she was re-assigned and required to report at the respondent's Manila office for further instructions.7 [Original Record, p. 67.]

On November 27, 1989, respondent agency terminated her services for abandonment when she failed to report for work in her new assignment.8 [Original Record, p. 68.]

On November 30, 1989, petitioner filed with the Labor Arbiter an amended complaint charging respondent with underpayment of wages under R.A. No. 6640 and harassment.9 [Original Record, p. 25.]

On June 26, 1990, Labor Arbiter Daniel C. Cueto rendered a decision the dispositive portion of which states:

On July 20, 1990, respondent E & R Security Agency, Inc. filed with the National Labor Relations Commission, National Capital Region, its Appeal Memorandum, in support of its appeal from the decision of the Labor Arbiter.

On June 25, 1991, the National Labor Relations Commission issued a resolution denying the appeal on the ground of non-perfection due to lack of appeal bond and that there was "no compelling reason or sufficient justification to disturb the contested decision, it being substantially supported by the established facts and applicable law and jurisprudence."11 [Original Record, pp. 93-97.]

On October 7, 1991, the decision having become final, on petitioner's motion, the Labor Arbiter issued a writ of execution on the reinstatement aspect, but it was not implemented because the monetary aspect of the decision remained to be determined.12 [Original Record, pp. 118-119.]

On November 8, 1991, petitioner asked the Labor Arbiter to issue an alias writ of execution based on the completed computation of back wages in the amount of P 104,396.00 worked out by NLRC's Research and Information Unit. On November 19, 1991, NLRC Sheriff Max L. Lago issued a Notice of Garnishment which was served on private respondent's deposit account with the Philippine National Bank, PNC compound Branch, Diliman, Quezon City, in the amount of P 105,296.00 inclusive of the execution fee of P1,000.00.

On November 27, 1991, the Labor Arbiter directed the Philippine National Bank to release the garnished amount and to make it payable to the NLRC cashier for the account of petitioner pending ultimate release to her. Accordingly, the PNB issued Manager's Check No. AF 90-8881 dated December 6, 1991.

Meantime, on December 3, 1991, respondent E & R Security Agency, Inc. filed with the Labor Arbiter13 [Original Record, pp. 141-144.] an Urgent Ex-Parte Motion to Quash the Alias Writ of Execution on the ground that there has been a change in the situation of the parties which makes the execution inequitable. Respondent contended that petitioner Torres accepted employment from another security agency without previously resigning from it.

On February 2, 1992, the Labor Arbiter issued an order for partial execution directing the release of the uncontested salary differential amounting to P15,523.48, to be deducted from the amount of P 105,396.00, and to withhold the balance thereof, pending resolution of the Motion to Quash the alias Writ of Execution.14 [Original Record, pp. 132-134.]

On March 19, 1992, petitioner filed with the National Labor Relations Commission a petition for mandamus and injunction to compel the Labor Arbiter to issue an order directing the NLRC Cashier to release the entire amount deposited with the latter to petitioner.

On August 11, 1992, the National Labor Relations Commission issued a resolution denying the petition for mandamus and injunction and ordered Labor Arbiter Daniel C. Cueto to immediately resolve respondent E & R Security Agency's Urgent Motion to Quash Writ of Execution.

Hence, this petition.15 [Filed on September 25, 1992, Rollo, pp. 2-16.]

The sole issue raised is whether or not the NLRC committed grave abuse of discretion in ordering the Labor Arbiter to resolve the motion to quash alias writ of execution.

Petitioner contends that the release of the judgment award is purely a ministerial duty of the Labor Arbiter.

The petition is impressed with merit.

Execution is the final stage of litigation, the end of the suit. It can not be frustrated except for serious reasons demanded by justice and equity.16 [Original Record, pp. 197-198.] In this jurisdiction, the rule is that when a judgment becomes final and executory, it is the ministerial duty of the court to issue a writ of execution to enforce the judgment. A writ of execution may however be refused on equitable grounds as when there was a change in the situation of the parties that would make execution inequitable or when certain circumstances, which transpired after judgment became final, rendered execution of judgment unjust.17 [Republic vs. NLRC, 244 SCRA 564 (1995)] The fact that the decision has become final does not preclude a modification or an alteration thereof because even with the finality of judgment, when its execution becomes impossible or unjust, it may be modified or altered to harmonize the same with justice and the facts.18 [Rodriguez vs. Project 6 Market Service Cooperative, Inc., 247 SCRA 528 (1995)]

The respondent agency's contention that there has been a change in the situation of the parties making execution inequitable because petitioner accepted employment from another agency without resigning from it is patently without merit. In the recent ruling of the Court, we said that the rule enunciated in Pines City19 [Pines City Educational Center vs. NLRC, 227 SCRA 655 (1993)] no longer controls. Now, the rule is that back wages awarded to an illegally dismissed employee shall not be diminished or reduced by the earnings derived by him elsewhere during the period of his illegal dismissal.20 [Surima vs. NLRC, 291 SCRA 260, 268-269 (1998), citing Bustamante vs. NLRC, 265 SCRA 61 (1996)]

In this particular case, the decision is final and, in fact, the amount of P 105,396.00 representing the sum total of the salary differentials and back wages awarded to petitioner has been garnished from the account of respondent agency with the Philippine National Bank (PNB) with no opposition or resistance and it is the ministerial duty of the Labor Arbiter to release the money to petitioner.

WHEREFORE, the Court GRANTS the petition. The resolution of the National Labor Relations Commission in NLRC NCR Case No. 00-01-00137-90 is hereby SET ASIDE. The Court DIRECTS the Labor Arbiter to order the immediate release of the balance of the judgment award to petitioner.

No costs.

Davide, Jr., C.J., (Chairman), Puno, Kapunan, and Ynares-Santiago, JJ., concur.