Marriott Corp. is selling its 514-acre tract on Interstate Route 66 beside the Manassas national battlefields -- a site touted by Prince William County officials as their most prestigious office location -- to a Fairfax County developer.

Pete T. Scamardo, president of Centennial Development Corp., said he plans to build corporate office parks and light industrial space in a campus setting on the property, most of which is wooded, while Marriott is reserving 15 acres for future development of two hotels.

County Board Chairman G. Richard Pfitzner described the deal this week as a "coup" for Centennial. "They have captured the crown jewel in our industrial heartland," he said.

The county's plans earmark the I-66 corridor as Prince William's major employment center of the future, and county officials long have said that whatever is constructed on the site -- the gateway to the office and industrial area -- should set the tone for quality development in the western part of the county.

To that end, county officials fought vigorously two years ago to have the State of Virginia build its Center for Innovative Technology, a clearinghouse for industrial research projects, on the Marriott site, but lost out to a site that straddles Fairfax and Loudoun counties.

Marriott assembled the tract more than a decade ago with the intention of building a King's Dominion-style amusement park. But that proposal unleashed vehement opposition from local residents, who successfully challenged technicalities of the rezoning procedure in court. Marriott decided against filing a second rezoning request, and the site has lain dormant.

Centennial, however, has little to fear from the leader of that fight: "Perhaps all the people who so deeply resented our fighting an amusement park . . . will now realize we are better off," Annie Snyder said as Centennial unveiled its plans.

Although county officials are greeting Centennial's $8 million purchase warmly, the company's development plans appear to be less grandiose than those the county had hoped for. Pfitzner acknowledged that the county wanted to lure a "Xerox or another IBM to the site."

But failing that, Centennial's plans to build space for lease that is suitable either for offices or light industrial use still will be a shot in the arm to economic growth in the county, said Dyan Lingle, the county's economic development officer.

"We don't have any speculative space right now. I'm losing potential clients because we have no ready-built space to offer," she said.

Centennial's announcement, along with plans for three other office parks on the I-66 corridor unveiled in the past year, should solve the shortage, Lingle said.

*Holladay Corp. of Washington has a rezoning application on file for a 126-acre business park east of the Marriott site in the northeast corner of the intersection of I-66 and Route 234 in Manassas.

*Maryland developer Eugene I. Siegel, president of LandServices Inc., has just won approval for a 101-acre business park in Gainesville, alongside I-66.

*Further west, Robert Trent Jones, an internationally known golf-course architect, is drawing plans for corporate office parks as part of his golf resort on the banks of Lake Manassas, west of the I-66 and Route 29 interchange in Gainesville.

Centennial's property is north of I-66, about one mile west of the Manassas exit.

Not only will Centennial's project be a gateway on I-66 to Prince William's future commercial centers, it also could unlock industrial land to the south of I-66. The county has designated about 7,000 acres between Manassas and Gainesville for industrial use, but the area has poor road access, relying on two-lane country roads that spill onto congested Route 234 in Manassas.

County plans show a four-lane highway called the Manassas Bypass running northward through the industrial land and intersecting I-66 at the Centennial property. Centennial's president, Scamardo, said he is talking with county officials about building a full interchange that connects his property with I-66 and the proposed bypass.

Until that interchange is built, development at the Centennial property must be limited, because Route 29 to the north of the site has limited traffic capacity, according to John Schofield, the county's deputy planning director. Neither the state nor the county have set aside money for that interchange, so who pays for it will be part of the negotiations during the rezoning process, Schofield said.

Centennial has hired the planning firm of Wallace, Roberts and Todd, which worked on Baltimore's Harborplace, to draw up development plans for the site. Scamardo said he has set no date for completing the plans or for filing a rezoning application with the county. The land currently is zoned for agricultural use, but planned for a corporate office park.

Centennial is the largest commercial developer in Reston, where it has constructed 1.5 million square feet of office and research and development space, housing such tenants as Sperry Corp., Tandem Computers and Piedmont Airlines. Centennial is constructing the first phase of a 2-million-square-foot, mixed-use project called Centennial Gateway at Fairfax Center west of the Fair Oaks Shopping Mall.