A group of black state legislators from Prince George's County is seeking to increase its power over county patronage jobs by introducing legislation in the General Assembly that would enlarge the county's elections and liquor boards.

State Sen. Decatur Trotter has filed legislation in Annapolis that would enlarge each of the boards from three members to five to allow blacks to serve on them. Members of the boards are appointed by the governor.

Members of the county's legislative delegation, who heard the proposals for the first time at a public hearing last week, will not vote on the measures until the start of the legislative session in January.

But the cost and the motives behind Trotter's plan already are being cited as problems by some of those who would have to vote and those who would have to implement the legislation.

Lou Panos, a spokesman for Gov. Harry Hughes, said that, in general, the governor does not favor quotas to achieve black representation, although he believes that such representation is necessary. Said Panos: "Once you begin using figures as something more than guidelines, you run into a double-edged sword."

Because each election board member gets $5,000 each year for the two-year terms, board President Mary E. Devaney said that Trotter's plan could cost $20,000 or more for each term. Alternates are paid $25 for each meeting they attend.

"I favor the bill," said state Sen. Thomas V. Mike Miller Jr., the leader of the county's Senate delegation, which sends its recommendations for such appointments to the governor. "The only question is, who funds it, the state or the county? If the county funds it, okay. But if it's the state, I don't think we can get that passed."

Local jurisdictions now pay the salaries of election board members, and County Executive Parris N. Glendening said that he would prefer to see the governor appoint a black member to the three-member board rather than the county footing the bill for an expanded election board.

"People don't have a life claim to any board," he said. "We've got to get serious about sharing power and we've got to do it aggressively and openly because it's the right thing."

The county could better use the money that additional board members would cost, Glendening added.

Local bills that are delegation-supported and have limited impact usually are passed routinely as a courtesy by both houses of the legislature. But they must first receive local delegation support.

Under Trotter's twin measures, the county's three-member boards of Supervisors of Elections and of Liquor License Commissioners would be expanded to five members, with the understanding that one new full-time member on each board would be black. The only black currently serving on either county board is Democrat Lona Hatter from Landover, an elections board alternate.

Liquor board members get $12,000 a year, and Chairman Robert S. Miller is paid $13,000. The board's operations are financed by county liquor license fees.

"We are trying to put blacks on boards where they've never been," Trotter said, citing the recent appointment of Deputy Sheriff Clarence Norman, the first black to serve in that county post. "We find we either have to remove someone from the current board or put someone else on it altogether."

Given that choice, Devaney said, she would rather support Trotter's bill than risk losing her appointment to what Miller described as a "patronage job." Board members' current appointments expire June 1, 1985.

"Whether you're black or white on the board, I don't see personally where that makes a difference," Devaney said.

Devaney and elections board administrator Robert Antonetti, a paid staff member, pointed to recent record election registration figures as an example of how efficiently the board is operating. Elections officials reported that more than 300,000 residents registered to vote in the Nov. 6 general election.

"Are we going to keep increasing the board every time another group comes along who wants to be represented?" said Antonetti, who is also the president of the Maryland Association of Election Officers.

Baltimore, he said, has a 55 percent black population and still manages to get black representation on its three-member election board. One of the city's board members and both of its alternates are black.

"Let the governor decide," Antonetti said. "You don't need to featherbed the board and cost the taxpayers of Prince George's County money.