Fairfax County developer John T. (Til) Hazel has proposed a land swap with the county park authority that could allow him to make millions if the land were rezoned.

The deal has drawn fire from some local politicians and citizen groups, who say Hazel could profit enormously at the county's expense.

Hazel's development firm, Hazel Peterson Companies, wants to give the county 44 acres of park land not far from Fair Oaks Mall. He said he would build $1 million of badly needed park facilities on the site for the park authority, which cannot afford the project.

In return, Hazel wants a 36-acre park, now owned by the authority, that lies east of Stringfellow Road, abutting land he already owns.

Hazel Peterson officials said the deal is straight and clean, and county supervisors whose constituents would benefit from the playing fields Hazel has promised are lined up behind the deal.

There's just one catch, according to Supervisor Audrey Moore (D-Annandale) and citizen groups such as the Fairfax County Taxpayers Alliance: If Hazel manages to rezone the land he's seeking from residential use to commercial, it could more than triple in value and render the deal inequitable.

The land in the area already is extremely valuable. If Fairfax Center Park, the land Hazel wants, were zoned for office use, according to Moore and real estate agents in the area, it could be worth $6 million to $10 million. If it were zoned for even denser development, it could be worth more.

"It's a rip-off of the taxpayers," said Moore. "The park authority should put it up on the open market and see what they can get for it."

The land Hazel wants is next to the Fair Lakes development, a 620-acre project conceived by Hazel that is one of the largest commercial developments undertaken in the Washington suburbs.

"Why swap the park land in the first place?" agreed Harold L. Dotson, a director of the county Taxpayers Alliance. He said the county could rezone the land, and the park authority could then reap the benefits of selling it to the highest bidder.

Curiously, Hazel gave the county the land he now seeks in a similar trade nearly two years ago. The land was meant to be used for playing fields. Since then, however, little construction has taken place at Fairfax Center Park because the park authority is strapped for cash.

Hazel Peterson spokesman Bob Kelly said the company wants the Fairfax Center Park land back because it is the site of the nearly completed Fair Lakes Parkway, one of four access points to the sprawling, $460 million Fair Lakes development. Construction is under way on the preliminary phases of the Fair Lakes project.

"We want to be able to control what happens to that land," said Kelly. "We want it to be ours." He said the firm bought the thickly wooded land it is now offering the county last year with the swap in mind.

In a March 1 memorandum to the members of the county park authority, assistant parks director Louis A. Cable wrote: "It is the intent of Hazel Peterson to rezone the Fairfax Center Park Area to light office . . . . " In an interview yesterday, Cable said high-ranking officials of Hazel Peterson had told him of the firm's intent.

Kelly disagreed. "We never said that to Lou," he said. "We have no specific plans for what we would do with that piece of land." Hazel could not be reached for comment.

Both the county park authority and the county planning commission must give their assent before the land swap could take place. Park authority officials say they support the deal.

Kelly acknowledged it was possible the firm would seek to rezone the land if the land swap is approved by the park authority. A rezoning requires the approval of the county Board of Supervisors.

Supervisor James M. Scott (D-Providence), whose district includes the Fairfax Center Park site and whose constituents "desperately need" additional athletic facilities, said he supports the trade.

"The trade is taking place on the basis of the current zoning," he said. He said he would oppose any bid by Hazel to rezone the property to permit more profitable office buildings on the site.