A developer has offered land for a new Fairfax County government center at about a tenth of the $5.5 million county supervisors have already agreed to pay to move the government from cramped quarters in Fairfax City to a site west of the city.

The offer from developer Milton V. Peterson, made through his attorney, John T. Hazel Jr., is a complicated package deal that would hinge on the county's promise to use the money it would save to start building a large portion of the proposed Springfield Bypass, a major cross-county artery.

The proposal was greeted with annoyance by Supervisor Marie B. Travesky, whose Springfield district includes both the 150-acre Smith-Carney tract between Rte. 29-211 and I-66, where the government is scheduled to be moved, and the newly offered property a few thousand feet to the north.

Travesky referred to the long and difficult process of selecting the Smith-Carney site and said, "I guess we are going to have to spend time looking into it [again]... I am very unhappy that it has come up at this time."

Both Peterson and Hazel own considerable tracts of undeveloped land -- "several hundred acres," according to Hazel -- that would be benefited by construction of the Springfield By-pass.

Under terms of the offer, the county would be sold about 90 acres for $7,000 an acre and would have to reacquire about 55 acres adjoining the county previously deeded to the County Park Authority.

"I am talking about (spending) $600,000 rather than $5.5 million," Hazel said.