The Federal Highway Administration agreed yesterday to lift temporarily its controversial order opening up 1,544 miles of Virginia primary highways, including parts of Lee Highway and Leesburg Pike in Northern Virginia, to 65-foot-long double trailer trucks.

But in return Virginia officials said they will consider on a truck-by-truck basis requests for permits allowing the big rigs to use the disputed routes until a permanent agreement is reached.

"I think we reached an excellent compromise . . . We bought time until July," Virginia Highway Commissioner Harold C. King told a Richmond news conference. "I'm tickled to death we didn't have to go to court."

The state Highway and Transportation Department, which had threatened to sue the federal government over its order opening the roads, has promised to grant each of the big truck requests within 24 hours unless it can show a specific safety problem, particularly that requested routes are too narrow to accommodate the large rigs.

King said he couldn't estimate how many trucks might apply. "I don't think there will be a great number."

By July 1, the state will submit its final recommendations for twin trailer routes to the federal highway agency. It will complete its review by Oct. 3 and announce the roads open to the rigs. Virginia highway spokesman Joseph Presbrey said yesterday the state anticipated that the number of miles that will then be opened to the big trucks "might be close" to the number of miles initially proposed by the Federal Highway Administration.

Northern Virginia officials, who have been among the fiercest critics of the twin trailers, were far from satisfied.

"What if you get 20 ad hoc requests for permits and suddenly these trucks are all over the place?," said Shiva Pant, the Fairfax County transportation director.

The dispute over the trucks results from the Surface Transportation Assistance Act of 1982, which increased gasoline and diesel fuel taxes five cents a gallon. The law also required all states to accept double-trailer trucks on the interstate highways and to designate other non-interstate roads that the trucks could use.

On April 6 state officials say they were shocked to discover the FHwA's regulation in the Federal Register designating the Virginia primary roads to be opened to the big trucks. After repeated protests, King met Friday with Federal Highway Administrator Ray A. Barnhart and ironed out the compromise.

If yesterday's agreement failed to completely satisfy truck critics, the truckers themselves appeared mollified. "I say the truckers can live with this if they state officials use the reasonable approach in granting the permits that Mr. King has assured me," said L. Ray Ashworth, executive vice president of the Virginia Highway Users Association.