Prince George's County will receive only about $3.5 million this year for its magnet school program -- significantly less than the $12 million requested -- under the budget Gov. Harry Hughes will present this week, State House sources said today.

Another $2.5 million in additional money for county schools will come from funds Hughes has budgeted to expand a funding formula enacted two years ago to provide special assistance to elementary and secondary education.

Although the extra $2.5 million is not targeted for desegregation purposes, County Executive Parris Glendening said that as a "practical matter" the money likely would assist that program.

When combined, the $6 million in additional funds still would fall drastically short of the cost of the magnet plan and, if approved by the General Assembly, could "cast a long shadow" over the desegregation program implemented in the fall, a school spokesman said. The program established special offerings in 12 predominantly black schools to draw white students.

The $6 million in new funds comes on top of $5.9 million the county already was scheduled to receive in general education aid under the formula proposed by a gubernatorial commission headed by former U.S. attorney general Benjamin Civiletti. The county also will get about $350,000 under a "compensatory aid" program for special education students and a like amount for its community colleges.

Although Prince George's officials said they were pleased to receive any extra funds for education, they expressed disappointment that Hughes did not target more for the magnet program, expected to cost about $50 million during the next four years.

"We were expecting a minimum of $6 million" for magnet schools, said state Sen. Thomas V. Mike Miller Jr., a Democrat who is chairman of the county's Senate delegation. "We believe it's a state responsibility. We're talking about desegregation by court order."

The ambitious magnet program was implemented in response to a court order to improve desegregation in the county's 175 schools.

State aid of $3.5 million, said spokesman Brian J. Porter, "would mean a severe shortfall in funding. We're depending exclusively on the state . . . . It would certainly cast a long shadow over our plans at the moment. We'd have to begin serious discussions."

School Superintendent John A. Murphy could not be reached for comment. Glendening said even if no additional state aid is forthcoming the magnet program will go ahead.

"My commitment is that education, this budget year, will make a dramatic step forward," he said.

He added, however, that a low allocation by the governor "makes the achievement that much more difficult."

Murphy has endorsed an energy tax on county homes and businesses as a means of raising $15 million. Glendening also has hinted at new revenue sources and the possibility of making "internal adjustments" to save money, but has refused to elaborate on what he has in mind.