Prudential Insurance Co. of America announced plans yesterday to build a $65 million office complex park in Greenbelt adjacent to the beltway.

Prudential officials said the company paid about $2.5 million for the 37-acre site which Prince George's County officials have long touted as a prime site for the type of white-collar development the county is trying to attract.

Prudential said tenants have not yet been lined up for its office complex, but a planning consultant for the insurance company said the project had received "several national inquiries, corporate headquarters types."

The consultant, Kenneth H. Michael, said his company plans to begin work in a few weeks on its headquarters on the edge of the site, in a five-story office building that also will house the newly chartered Jefferson State Bank, a savings and loan association, a stock brokerage and several law firms.

Prudential announced the purchase yesterday with county executive Lawrence J. Hogan. Hogan called the development "exactly the kind of business we are seeking to bring to Prince George's County."

The insurance company expects to build about 400,000 square feet of office space over the next five years on the site, the so-called golden triangle bounded by the beltway, Kenilworth Avenue and Greenbelt Road. Preliminary plans for the area include 10 office buildings, a restaurant and a motel.

The development is a substantial addition to Prudential's approximately $95 million worth of projects already under way in the Washington-Baltimore area. Those projects include a 15-story building nearing completion in Tysons Corner, a 48-acre office and warehouse park in Merrifield, Va., and a warehouse complex in Fairfax County.

Prudential purchased the land from Kravco Inc., a developer and manager of shopping centers based in King of Prussia, Pa.

Other development in the area includes a 60,000-square-foot Cadillac dealership and a nearby Hilton Hotel, said Richard R. Pilski, Mayor pro tem of the city of Greenbelt.