Montgomery County's embattled housing authority, in an attempt to get more for its money and to diffuse neighborhood resistance, last week took steps to scatter public housing in the county, rather than construct units on one site.

In an unusual action, which the agency said was the first of its kind, the Housing Opportunities Commission (HOC) voted to accept $3.7 million in federal funds it had requested to build a 39-unit project on Mateny Road in Germantown, then immediately directed its staff to ask the federal Department of Housing and Urban Development for permission to abandon the project. The commission will seek an okay from HUD to use the money to purchase existing low-cost housing throughout the county.

Housing officials were unable to predict this week whether the federal agency would approve the transfer of funds. If it did not, an HOC spokesperson said, the commission would proceed with its original plan for the Mateney Road site.

The vote was a victory for Germantown residents who opposed the plan, but the overriding factor in the commissioners' decisions appeared to be cost and not a shift in philosophy. According to the housing commission's estimate, the $3.7 million would pay for nearly one-third more units under the "scattered site" plan than under the original "cluster" proposal.

In a "cluster project," the traditional concept of public housing, all units, usually apartments or town houses, are located on one site.

During the voting session, commissioners emphasized that the request to spend the federal money on scattered units should not be read as a change in HOC policy. Earlier this year, critics of the commission called for a major overhaul of its policy, charging that the HOC was unresponsive to community needs and wants. The Montgomery legislative delegation is now considering introducing 15 bills in the just-opened General Assembly session to limit the commission's powers.

HOC Director Bernard Tetreault said the agency still would consider clustered housing in instances where that type of project would best meet the needs of people waiting for homes. HOC clients in this category would include families with young children who need day care, residents with special transportation problems and handicapped persons. Currently, 8,500 families and individuals are on the agency's waiting list, and most should expect to wait at least five years before being placed, a housing spokesperson said.

Montgomery now has 1,800 units of subsidized housing. Nine hundred units are for the elderly; the remaining 900 are split equally between clustered and scattered projects.

The commission will meet Jan. 27 to discuss the possible purchase of another 33 scattered units in the county, separate from the units it hopes to purchase with the Mateney project money.

Tetreault said the question of whether the HOC's recent vote might be a Rosetta stone for future action could be moot.

"We're really talking about an issue that may not be an issue. I don't see us doing a lot with public housing in the future, with the current Reagan administration. The source of funding is just drying up."