The Loudoun County Board of Supervisors this week approved development of 330 acres on the south side of the Leesburg Pike west of Sterling Park as a 3-million-square-foot office park.

The park, to be known as the Loudoun Technology Center, will be erected on part of the site once known as the western Pocahontas tract and more recently called Cameron Glen.

The office park will be developed by Radnor/Loudoun Corp., a joint venture of Buchanan and Co. of Rockville and Radnor Corp. of Radnor, Pa.

Radnor Corp. is a subsidiary of Sun Co. Inc., a Pennsylvania-based petroleum production and refining operation.

The office park is being designed to lure high-technology corporations to Loudoun County, a fact that pleases Loudoun economic development officials and other developers who have been working hard to sell the advantages of corporate relocation to Loudoun.

During the past six months, Loudoun County has made major moves to grab its share of the burgeoning high-technology industry in the Washington area.

The new office park will be built between Sterling Park and the residential development known as Countryside.

The board of supervisors approved the blanket special exception the developer had requested despite the Loudoun Planning Commission's recommendation against approval, the developer said. The Radnor/Loudoun Corp. asked for that kind of exception to develop the project to keep from having to go back before the board to get a special exception every time a specific building within the development was planned, explained Joe O'Connell of Radnor Corp.

The Loudoun planning staff had supported the project contingent on a long list of conditions, many of which were imposed upon the project by the full board this week.

"As I understand it, most of those conditions were things that we proposed in our original sketches and plans submitted," O'Connell said this week. These conditions include specific setbacks and road improvements around the project.

Radnor/Loudoun also will widen Leesburg Pike in front of its development, provide left-turn lanes and install traffic signals deemed necessary by the Virginia Department of Highways and Transportation.

"When the back part of the property is developed, improvements will also be made to Route 638 where it is contiguous to our property," O'Connell said. "Improvements are also planned for Route 637."

The developer also must fund studies on the impact of the project on traffic along Leesburg Pike. Those studies are to be turned over to the Loudoun Planning Commission. The county also wants to see traffic circulation patterns within the project, O'Connell said. VDH&T officials have said they want more information about the overall traffic impact.

The site is convenient to the planned Center for Innovative Technology, which is to be built at the intersection of the Dulles toll lanes and Route 28, a fact developers hope will attract tenants. Buildings are being designed with high-technology tenants in mind.

"I do not see us building anything higher than three stories," O'Connell said. The developer would need permission from the board of supervisors to build anything taller than that because of a 35-foot height limitation on the site.

"We anticipate having 230 to 240 developable acres. I would expect about 3 million square feet of finished space," O'Connell said.

He said it may be possible to find "single users who may want 20 or 30 acres designed for their own particular usage." Radnor/Loudoun is willing to build to meet those needs, he said.

The development company plans to file preliminary site plans within two weeks. Final site plans will be filed by the end of this year or early January. O'Connell predicted construction would start next spring.

Radnor/Loudoun purchased the site from CSX Minerals Inc. of Richmond in early October for an estimated $8.5 million. The acreage was part of the total 1,600-acre package known as Cameron Glen. At the same time, Southmark Corp. of Dallas paid $18.1 million for more than 1,300 acres across from the Radnor/Loudoun tract on the north side of the pike. That site stretches to the Potomac River. The land is zoned for residential use, but a year ago, Loudoun officials rejected an application by CSX and Sunrise Development Co. for a planned community on the giant tract.

A spokesman for Southmark said no decision has yet been made as to how that site will be developed.

When Radnor/Loudoun bought the site, Robert Buchanan, president of Buchanan and Co., said the proximity to the Dulles Airport, the opening of the Dulles toll lanes and the governor's CIT project were all part of the attractiveness of the land.

Buchanan and Radnor Corp. have jointly developed Parkway Trade Center near Herndon and have major plans for development in the Ballston area of Arlington near the Ballston Metro station.