The 18-story Parkside Plaza building on Sligo Creek Parkway in Silver Spring is under contract to be sold for nearly $9.5 million to the Artery Organization Inc., which plans to condominium conversion.

However, the Parkside Plaza Tenants Association has organized to protect tenants interests -- "possibly by buying the building or to work out an accommodation with Artery or to seek another developer to work with us," said attorney Morris Altman, president of the newly formed group. Montgomery County law gives tenants the option to buy with 120 days after notice of condominium conversion plans.

The 250-unit Parkside was built in the mid-1960s by Edward and Samuel Perkins and Harold Kramer. Occupancy is limited to adults. Rents range from $400 to $525 a month.

Developer Edward Perkins lives in one of the apartments and says he plans to stay as a condo owner. His office is also in the building.

Ernest Erber, vice president of the tenant association, said that 211 tenants belong to the group. A $2 million down payment is being required as a deposit, he noted.

Henry Goldberg, president of Artery, said: "Our firm, which has experience in condo conversions of our own properties and which builds new rental units for the elderly, is equipped to work with tenants for their total interests. We will also do our own remodeling.

"I feel confident that we will be able to meet soon with the Parkside leadership and work out a program that will be mutually advantageous to all of the tenants and to us."

Erber said his group is contacting banks, attorneys, appraisers and engineers for assistance, believing that a tenant purchase "would result in saving thousands of dollar per apartment."