A majority of the Prince George's County Council has decided to block County Executive Lawrence J. Hogan's effort to install a black officer in a high-ranking post on the county police force, several council members said yesterday.

The council members, who have been heavily lobbied by members of the county police union, plan to cut $40,000 out of the proposed 1980 budget for the police force - money that had been earmarked for a new lieutenant colonel's salary.

Hogan and Police Chief John W. Rhoads have said they wanted to fill the vacant lieutenant colonel's job with a black officer from another law enforcement agency.

Council members contacted yesterday said that they would prefer that Hogan create a new position in the department, a position exempt from the hiring and promotion requirements that govern most county police officers.

If Hogan wants a high-ranking black officer on the force, that new position should be filled with one of the 55 blacks currently on the 837-man force, council members said.

Creating such an exempt position involves voter passage of an amendment to the county's charter - something that could not happen before November 1980. Hogan had hoped to have a high-ranking black on the force by July of this year.

"I think everyone-the executive, all of us on the council and the police-are agreed that we need black leadership in the department," said council member Gerald T. McDonough.

"The disagreement is on how to go about doing it. The FOP [Fraternal Order of Police] feels strongly that the man should come from inside and that an exempt position should be created for him. I think I'm inclined to agree with that.

"If the FOP doesn't want it that way, I don't think we're inclined to fight them, especially where it concerns a uniformed policeman."

Hogan pointed out yesterday that under the county merit system the county has a right to look outside to fill any position that opens up if there are five or fewer persons at the rank below it within the system.

"If the council doesn't like this idea then I think they should amend the merit system to prevent anyone from going outside." Hogan said. "I said originally that we were seeking the best candidate and I hoped he would be black. If we promoted a sergeant [there is one black sergeant on the force] just because he was the highest ranking black, that would be tokenism. I'm not interested in that."

Police union President Laney Hester, who has been the strongest opponent of Hogan's plan, said yesterday he thought it would hurt police morale to bring a man in from outside.

"I think if they brought someone in and stuck him in our pension system and just said, 'zap' you're a lieutenant colonel, that would upset a lot of guys-especially the black guys, I think," Hester said.

"The charter amendment for an exempt position puts it to the voters and then if they want they can stay inside and appoint the best qualified black on the department then."

Police Chief Rhoads has told Hogan that he would favor legislation exempting every position in the higher ranks, from captains up, leaving all these appointments up to the chief. Hogan said yesterday he had "no problem" with that concept. "That way the chief wouldn't come in and have no control over his command staff like now." Hogan said.

If the council does decide in the next two or three weeks to eliminate the money from the budget, a charter amendment to create one or more exempt pisitions could not be voted on until the next congressional election-1980.

"I know a lot of people, the FOP included, are lobbying against this idea," Hogan said. "But sometimes they forget that police morale is only one of our problems. We also have to be concerned with community morale."