The Prince George's County School Board, defying Executive Lawrence J. Hogan, ratified a contract with is teachers union last night that would cost more than Hogan has budgeted for teachers salaries next year.

Hogan said Tuesday that his proposed school budget would fund 3 percent salary increases for board employees. The contract ratified last night contains yearly increases of about 5 percent for the 6,700 teachers over the next two years.

School officials also announced last night they had reached tentative agreements with the school board's two unions of blue-collar workers that also promise 5 percent raises in each of the next two years.

The board's action means that Hogan and the school board will take their battle over employe salaries to the County Council, which has final authority over county spending.

Hogan's argument that the school board should renegotiate its teachers' contract to reduce salary increases was attacked both by board members and union leaders last night.

School Superintendent Edward J. Feeney urged the board to ratify the contract, and board Chairman Norman H. Saunders declared. "The board is engaged to the Prince George's teachers, so let's tie the knot."

Three board members argued that the board should not ratify the contract until funding for the increases was assured. "By ratifying tonight, we lose the ability to bargain with the County Council and move into a confrontory position," said board member Susan B. Bieniasz.

Both Bieniasz and board member Angelo I. Castelli abstained from the contract vote.

Meanwhile, Toby Rich, the president of the Prince George's County Educator's Association, which represents teachers, said that a coalition of PTA leaders, school special interest groups, and school board members had already formed to "support the total education budget before the county council."

"I don't think Mr. Hogan knows what he is doing." Rich said. "He has attacked vital and valuable educational programs, and he has made inflammatory statements and insinuations that show no sensitivity.

"The teachers have no intention of renogotiating their contract," Rich said. "The die has already been cast. It's apparent that most of the board is wholeheartedly against Hogan.