A national real-estate developer that hopes to build a sprawling office park at Fort Meade would be required to at least pay property taxes, according to an opinion from the state attorney general's office.

The 19-page opinion appears to offer the legal underpinning for state legislation that would permit the state and Anne Arundel County to negotiate with Texas-based Trammell Crow Co., which wants to build a $700 million office project on Fort Meade property for up to 10,000 workers arriving as part of a major defense expansion.

Anne Arundel County and the state have been pressing Trammell Crow and Fort Meade to help defray the costs of road improvements needed to ease traffic associated with the proposed 1.7 million-square-foot project on 173 acres on the post's perimeter. Trammell Crow and the Army have been negotiating for more than a year on a specialized agreement for what is known as an enhanced use lease.

The governor's office requested the opinion from Attorney General Douglas F. Gansler and received it last week as lawmakers began to consider the bill, which could also affect a lease deal at Aberdeen Proving Ground.

Military land is exempt from property taxes, but state and county officials said they think taxes can be levied on any private buildings and other facilities constructed on the bases.

For such lease agreements between the military and a private developer, the legislation would exempt property taxes if the developer negotiated with the state and the affected jurisdiction on an alternative payment that would "consider the total impact of the development."

Anne Arundel County Executive John R. Leopold, a Republican, said he views the state legislation sponsored by the O'Malley administration as a "helpful tailwind."

The Fort Meade office park probably would accommodate expanding intelligence and communications operations at the Army post. An estimated 22,000 workers are expected to arrive at Fort Meade over the next four years as part of the base realignment process known as BRAC.

A five-mile portion of Route 175 near the Trammell Crow project is scheduled for a $700 million overhaul, and Leopold said he wants the company to pay its fair share.

Representatives of Fort Meade and Trammell Crow said they are reviewing the legal opinion and the legislation, and they declined to comment on either. The two sides entered into exclusive negotiations in November 2006.

Mark S. Corneal, a senior vice president at Trammell Crow, said he is optimistic that a deal will be made soon and that construction will begin this year.

Trammell Crow would build two golf courses and provide other services over a 50-year period in exchange for being allowed to build on federal land. Corneal reiterated that Trammell Crow is "fully prepared to reimburse a provider for any services used."

The legal opinion said counties could not charge impact fees as a way of offsetting the burden that development places on roads and other infrastructure. However, Leopold said the bill would give the county latitude to seek a payment "in lieu of impact fees."

If the office park was built on private land, Trammell Crow would be required to pay $6.7 million a year in local and state property taxes, county officials have said. Impact fees for such a project would be $3.5 million, they said.

Meanwhile, Sen. Barbara A. Mikulski announced yesterday $865 million in projects for BRAC-affected sites as part of $1.28 billion construction package at Maryland's military installations.

phill.mcgowan@baltsun.com