Co-op owners at the Promenade in Bethesda have decided to hire legal counsel to protect their interests in possible legal battles with American Invsco, the huge apartment converter that has been trying to turn the 1,072-unit complex into a cooperative, sources said this week.

Owners (technically shareholders in the cooperative corporation) have said they now fear that Invsco, strapped for money, may abandon them and leave them with large debts. Invsco has not paid its January and February assessments at the Promenade for the units it still owns at the building, and is delinquent on its state and local taxes.

In addition, co-op sharesholders say the converter has large debts outstanding with Chase Manhattan Bank, which they believe they would be liable for if Invsco defaults and the bank takes over.

David Varner, a spokesman for American Invsco in Chicago, said the company would "absolutely not" abandon the cooperative.

Still, the co-op shareholders said they are planning for that possibility.

"If the developer left the Promenade owing just two months' assessments, each minority shareholder coop owner could be assessed as much as $1,000," a hand-written flyer calling a shareholders' meeting this week said.

"The developer has owed the corporation (us) up to $1 million at a given time. This debt is unsecured, and we could be left with this debt if Chase Manhatten Bank were to foreclose on the building," the flyer continued.

"We are afraid American Invsco will abandon the building or it will go up for tax sale," said one Promenade resident.

Varner said Invsco is still challenging a large increase in the property taxes at the cooperative, and that is why the tax bill has not been paid.

The company recently fired all but two staff members at the Promenade in another cost-saving effort. Those fired include the resident manager, the property manager, the head of contract administration, and two of four maintenance personnel at the building, according to sources at the Promenade. Other Invsco employes were fired earlier.

Varner said the firings were made to "strengthen management and administration of the property." The fired employes will be replaced by Invsco, he said.