Alexandria Commonwealth's Attorney William L. Cowhig said yesterday that special prosecutor Edward J. White has agreed to drop the remaining bingo-related gambling charge against him in exchange for Cowhig's resignation next month.

"As far as I'm concerned," said Cowhig, "it's all over."

The embattled chief prosecutor, who was indicted Aug. 3 on three felony charges, had temporarily relinquished his office pending outcome of the trials. He has been acquitted in separate trials of bribery and illegal gambling charges, and faced trial March 5 on a second gambling charge.

Cowhig said yesterday that his attorneys, Blair D. Howard and Louis Koutoulakos, met with special prosecutor White on Friday afternoon. According to Cowhig, White agreed to drop the remaining charge -- running a gambling operation in the form of bingo games.

Cowhig, 53, said his resignation will become effective on or about March 5. He said he will return to private practice and that he had decided not to seek reelection to office.

Koutoulakos refused last night to discuss any possible bargain reached with the special prosecutor on behalf of his client, and White declined all comment.

A motion to dismiss the gambling case must be granted by Prince William Circuit Court Judge Percy Thornton Jr. who was designated to preside over Cowhig's trials after three Alexandria Circuit Court judges disqualified themselves.

Reached last night, Judge Thornton said the arrangement "is news to me, but if they have worked out a deal the court would have no reason to go contrary to that." Thornton said the case could be disposed of before March 5 if White requests an earlier court date.

"Since August, I became very close to God," said Cowhig, adding that he had been "reborn" in the Christian faith. "The closer you are to God, the harder Satan works on you. This whole thing has been the work of Satan," he said.

"I thought I did a good job. I'm not giving in. The only reason I'm doing this is for the integrity of the office," he said.

Cowhig was first elected commonwealth's attorney in 1973, and was unopposed for reelection in 1977. His current term would have expired Dec. 31, 1981. first Virginia commonwealth's attorney ever to be indicted while in office.

Virginia law provides that in the event of a vacancy in the office, the chief judge of the Alexandria Circuit Court shall appoint an interim commonwealth's attorney to serve until the next general election, which will be held in June.

Cowhig had declared last week that even if acquitted in the pending gambling trial, he would resign his office and then seek reelection based on a "public vote of confidence."

In announcing his decision yesterday to resign permanently, Cowhig said it had "absolutely nothing" to do with a newly resurfaced allegation that he had solicited a sexual bribe four years ago from the wife of a defendant being prosecuted by his office.

According to the woman, Sherry Chenault, Cowhig had solicited an act of oral sodomy in his city hall office in 1975 in exchange for a promise of leniency for her husband, who was facing trial on a drug charge.

Last Friday, Acting Comonwealth's Attorney John E. Kloch asked Alexandria Circuit Court Chief Judge Wiley Wright to appoint a new special prosecutor to reopen the investigation into the allegations.

Sources close to the continuing Cowhig probe told The Washington Post that Kloch asked for the new prosecutor after he learned from city police officials that Cowhig allegedly had confided to a police polygraph operator in 1975 that the sex act had occurred and, further, that three highranking police officials may have been involved in a "cover-up" of the incident.

The allegations surrounding the polygraph test, which Cowhig took at his own request, and charges of a police coverup came to light last July during a police secret investigation into Cowhig's role in the city's bingo scandal.

Cowhig has flatly denied the allegation publicly and said yesterday he hoped that his resignation would eliminate the need for the new special prosecutor.

Kloch indicated yesterday that the investigation would continue.

"As far as I'm concerned, my letter to the judge takes it out of my hands," said Kloch.

Judge Wright said yesterday, "I am going forward and will appoint a special prosecutor."

In his letter to Judge Wright, Kloch cited "prosecutorial misconduct, including criminal activity" in reference to Chenault's 1975 accusation.

Meanwhile, attorney Roger Amole, who defended Daniel Chenault on the 1975 drug charge that prompted the sexual allegation against Cowhig, said last night that he is considering a motion for a retrial of that case. Daniel Chenault was convicted on the charge and served 16 months of a five year sentence in prison, and currently is serving a separate jail term after being convicted on a subsequent drug charge. Cowhig made no sentencing recommendation at the time of Chenault's originial conviction.

Yesterday, Cowhig said, "I have been as happy and as peaceful in the last four or five months as ever before in my life."

Of his highly publicized trials, Cowhig said, "I was not found guilty of anything, but sometimes people use excuses to rationalize reasons for acquittals." (They say) "Good lawyers, the witnesses are liars and so on, without saying that the guy was innocent."

Cowhig said yesterday that it would be "a hassle" to remain commonwealth's attorney and that city officials, whom he has accused of waging a systematic campaign to oust him from office," would keep harping on it.

Last week, in a "Dear Bill" letter to Cowhig, Kloch and four members of his staff threatened a mass resignation if Cowhig returned to office. Sources said their ultimatum, which Cowhig called "a sneak Pearl Harbor attack," was based on the Chenault incident.

"I wanted peace of mind. My decision was based on the realization that there would be certain people in the city who would nag, nag, nag until I resigned," Cowhig said.

Cowhig said yesterday, "Mr. White has not appeared to want to get every drop of blood from me." The plea bargain, Cowhig said, was agreeable to the special prosecutor "as a reasonable disposition of the charges."

White was appointed last April to handle bingo-related charges after Cowhig himself called for a special prosecutor.

Asked if he would consider running for any public office in the future, Cowhig said, "The only office I ever wanted was the commonwealth's attorney."