The Prince George's County Council reelected William B. Amonett as its chairman yesterday in a 6-to-3 vote that exposed simmering acrimony and brought charges of sexism from the panel's three women.

In a vote that was controversial for different reasons, the county Board of Education voted 5 to 4 Monday night to elect Bowie lawyer Paul Shelby as its chairman, rejecting Vice Chairwoman Sarah Johnson's bid.

Amonett, 54, has served as chairman three times in his 11 years in office. Vice Chairwoman Hilda Pemberton, 43, was nominated first but rejected in a separate 5-to-4 vote.

Pemberton and her supporters said later that they were unhappy with the result because they felt that the time had come for a woman to be elected.

"There are intelligent beings here," said council member Floyd E. Wilson, who nominated Pemberton. "Females should be given at least one opportunity out of their four years here [to serve as chairman]. We have hogged this all along."

Frank Casula, a former council chairman who brokered votes for the elections of Amonett last year and Wilson in 1983, said yesterday that keeping Amonett in the chairmanship will guarantee a measure of continuity throughout 1986.

"If it were not an election year, I would have supported Hilda for the chair," Casula said.

"How insulting can you get?" council member JoAnn T. Bell countered. "To say you're good enough to do it next year and not this year?"

Pemberton said that she did not lobby for the council job but would have accepted it. "The rationale for keeping things to the status quo doesn't really have a whole lot of merit," she said. "No position should be sacred for any of us," she added.

Amonett said he made no deal to secure his reelection, and he said he was "humbled that there is at least a majority of the council that feels I've done a good job."

Voting for Pemberton in the first tally were Bell, Sue V. Mills, Wilson and Pemberton, with Amonett, Richard Castaldi, Anthony Cicoria, James Herl and Casula voting against her. In the vote on Amonett's nomination, Pemberton joined the majority who supported Amonett.

Those who voted against Pemberton said that sexism was not a factor in their decisions.

"I want Hilda, JoAnn and Sue to know I'll still hold the door for them," Herl said with a grin.

In the contest to head the school board, which has been led by women several times in the past, sex was apparently not an issue.

Johnson said she sees the vote that defeated her as a sign that "we are still very much a divided county," although the divisions are based more on geography than race. Johnson is black and Shelby is white.

Lesley Kreimer was unanimously elected vice chairwoman.

Several other members, however, said they did not share Johnson's perception of the vote and saw it instead as merely preference for one candidate over another.

"I don't read any mystery into it. People had made a commitment," said member Doris Eugene, the swing vote after members split 4 to 4 between Shelby and Johnson.

"I don't think there was any regional faction," said outgoing Chairman Angelo Castelli. "If there was any regional faction, it was created by Mrs. Johnson."

In a rare move and at the insistence of Johnson, the board publicly aired its division over who should be chairman. In the past, members have agreed to vote unanimously in public, despite often divisive votes in closed-door sessions.

"I wanted it to come out in the open. I didn't want to pretend all is well when it's not," Johnson said.