Prince George's County's police chief said yesterday that he intends to hire a black to replace Lt. Col. Thomas Davis, the police department's highest ranking black until he was forced to resign after three recruiters said he asked them to inflate blacks' test scores.

At a press conference at police headquarters in Forestville, Chief Michael J. Flaherty did not name any possible successors to Davis, an eight-year veteran of the force who headed the Bureau of Administration.

Flaherty said his request for Davis' resignation Thursday was based on a tape recording of a Jan. 24, 1983, meeting in which the three recruiters said Davis, who was their boss, asked them to change test scores a day after several black applicants failed the entrance examination. The recruiters said the tape was made with Davis' consent.

Although the police chief did not play the tape for reporters because he said it was at a police laboratory, he read from what he said was a partial transcript. He said that in that conversation Davis said, "You have people who have written 65 or 66 in these tests. There's no way in the world the people's score shouldn't be corrected to reflect that they passed the test." In another portion of the tape, Flaherty quoted Davis as saying: "If you don't want to manipulate the system to help them, we're not going to get to first base."

In an interview Thursday night, Davis denied any wrongdoing and said his words were misunderstood. He said he wanted the recruiters to encourage interested black applicants to study and retake the admissions test if they failed.

Yesterday he also said he was given the tape to listen to last week and he gave it back to the complaining officer. "Nobody is going to blackmail me with some tape," he said angrily. "I only listened to part of the tape," Davis added, and he said he could not remember precisely what he said in a conversation two years ago.

The three officers brought the tape to the chief's attention last week because one of them, Cpl. Roland Wilson, was scheduled to be transferred out of the personnel department, according to Flaherty and one of the recruiters, who asked not to be named. Wilson believed Davis was transferring him because he had not complied with requests to alter tests, according to Flaherty. The other two recruiters were Sgt. Edward Adams and Cpl. Wayne Hemphill. Flaherty said the officers did not alter the applicants' scores.

County Executive Parris N. Glendening said yesterday that he had talked with Flaherty several times in the past week about the Davis investigation and concurred with the chief's decision.

"It's a very unfortunate situation," Glendening said. He said he agreed that the position would probably be filled by a member of a minority. "We have several candidates in mind," he added.

Davis' resignation was a prime topic of discussion throughout the department yesterday, and many officers said they were surprised by the news. "It blew my socks right off my feet," one officer said.

Tom Lennon, president of the Fraternal Order of Police, said the union was supportive of Flaherty's actions and considered them to be "absolutely fair."

Davis' resignation comes at a tense time when many of the 170 black police officers in the 900-member department have formally complained to county officials about the promotion and hiring systems that they say are unfair to blacks. There are two black sergeants, and no blacks hold a rank higher than sergeant in the department. Blacks formed a separate organization last year and so far have been unsuccessful in negotiating changes that satisfy them, said the police union and county labor officials.

Officer Reginald Riley, a board member of the county's Black Police Officers Association, said yesterday, "Whoever they get to replace Tom should be a strong black to spearhead getting rid of discrimination in the department."

Davis, a retired Army officer, joined the department in 1978 as a human relations instructor. In 1981 he was appointed to the deputy chief position to oversee personnel and training and to improve minority recruitment. But others in the department said that he was generally considered an outsider and was never particularly popular among white or black officers.

John Rosser, former vice president of the county's NAACP chapter, said yesterday that he knew Davis well and was surprised and suspicious of the allegations. "It's odd that someone with his background would say something like that," he said.