The Federal Deposit Insurance Corp. has signed a contract to purchase nine acres near Arlington County's Virginia Square Metro station and is planning to build several high-rise buildings there to train and house its employes, officials said yesterday.

The project would create an employment center at a cost estimated at more than $100 million at what has been one of Arlington's least developed Metro sites.

FDIC spokesman Steve Katsanos said that the agency's precise proposal "has not been nailed down yet" but that it does not call for abandoning any of its offices in the District of Columbia. FDIC owns a headquarters building at 550 17th St. NW, across the street from the Old Executive Office Building.

According to the Arlington planning staff, tentative plans by FDIC call for the agency to build 1 million square feet of office and hotel space in up to six buildings. Two would probably be used for FDIC training and one for an employes-only residence or hotel, with the rest being rented to businesses, according to a county planning memo.

No one was able to estimate the cost of such a project yesterday. But using a rule of thumb in the development industry that puts the cost of such buildings at $100 a square foot, the complex would cost more than $100 million.

FDIC, which insures deposits in commercial banks and oversees bank failures, has about 7,000 employes nationwide and owns most of the buildings it occupies.

As many as 500 agency employes undergo training courses each year. "We have experienced a rapid rise in bank failures. It creates a need for more and better supervision," Katsanos said.

Gary Kirkbride, chief of the county's planning section, said that FDIC has notified the county that it may ask for an additional 380,000 square feet of building rights in exchange for providing a grocery store and a residential building there. The site is across Fairfax Drive from the Virginia Square Metro station on land owned by the George Mason University Foundation and a partnership that owns the Virginia Square shopping center.

John T. (Til) Hazel, a prominent Fairfax County developer who represents the foundation, said it signed a contract last week for the six acres of parking lots it owns adjacent to the university's law school. The law school site, owned by the state, would not be included in the development.

"It ended up being the best deal on the block," Hazel said of FDIC's offer, on which he declined to elaborate.

Officials of Virginia Square Ltd., the shopping center's owners, could not be reached for comment.

The county's plans for the area -- bounded by Fairfax Drive, Washington Boulevard, North Monroe Street and Kirkwood Road -- call for preserving the residential nature of the nearby neighborhoods and confining high-rises to the nine acres FDIC is buying.

The County Board, which would have to approve the FDIC plans, has adopted a detailed blueprint for the tract's development and a policy of encouraging the inclusion of a supermarket, cultural facilities and extra residential development in exchange for extra building density.

County Board Chairman Mary Margaret Whipple said the reported request for an additional 380,000 square feet "sounds quite high." She added that the inclusion of a grocery store there "is certainly very important for us" and the board would have to "work out something as we go along" on the proposed trade-off of density for a supermarket.

FDIC's proposal, she said, "sounds like a good addition to Arlington County. I think we would welcome them if we can work out the . . . land use issues."