The new owners of the massive Buckingham Apartment complex in Arlington, which has been embroiled in condominium conversion battles for the past year, said yesterday that they have guaranteed that 250 apartments will remain rental units for five years and have set aside another 50 units, with eight-year leases, for elderly and handicapped tenants.

Officials of the Michigan-based Hall Management Co., which bought the 980-unit complex a month ago, said yesterday that the company will maintain the entire development as rental property for now, and spend $5 million on sprucing it up, but will probably sell the complex in eight to 10 years.

If the Hall company decides within the next seven years to sell the project for condominium conversion, it has promised to give the Arlington Housing Corporation the first right to purchase 232 units. The AHC is a private, nonprofit corporation established for the purpose of preserving moderate-cost housing.

"It's a compromise," said Buckingham Tenants Association President Susan Korfanty, about the settlement negotiated between the tenants and the management company. "We're preserving some low- and moderate-income housing, but not as much as we would have liked to." Korfanty was a leader in the fight against the now-scrapped condominium conversion plans.

Richard Proffer Jr., an assistant vice president with the Hall management firm, emphasized that his company is not in the condominium conversion business. He declined to disclose how much Hall paid the former owner, the Chicago-based Stein Co., for the 42-year-old, sprawling complex located off Glebe Road.

Proffer and Marti Kohnke, another Hall vice president, said their firm also hopes to buy another 465 rental units in the complex owned by the Klingbeil Corp. of Ohio. The Buckingham complex includes a total of 1,800 apartments. An estimated 400 units have already been sold as cooperative apartments.

County officials, concerned about the threat of condominium conversion, have been carefully monitoring the fate of Buckingham, one of Arlington's largest sources of low- and moderate-cost housing.

"I'm glad it's going to be rental," Arlington County Board member Dorothy T. Grotos said yesterday. "It'll bring a lot of peace of mind to people. At least they won't be living daily with that uncertainty, and there will be some security."

After it purchased 1,200 units at Buckingham two years ago, Stein offered the apartments as cooperatives, but sold only about 400. When Stein sought to convert the remainder of the units to condominiums, the Buckingham Tenants Association sued to block the plan.

Korfanty, president of the association, said yesterday that the suit will be dropped as part of the new agreement with Hall, which will pay the tenants' $1,200 legal fee.

Under the terms of the agreement between the tenants association and the Hall company, the 250 units guaranteed to be available for five years will be rented at the competitive market rate, and rent increases on the apartments reserved for the elderly will be limited to 10 percent annually.

"I think there may be some dissatisfaction among tenants and it would have been nicer to achieve a larger portion" of guaranteed rentals, Korfanty said about the agreement with the Hall company. "But I hope people recognize that we have achieved something better than what , under the rights of tenants in Virginia, we would have been given."