The Alexandria Redevelopment and Housing Authority has fired City Manager Douglas Harman as its executive director in a move that effectively frees the independent agency from city-imposed restraints on its operations.

Citing what it termed administrative problems resulting from Harman's dual role, the board voted 5 to 2 at its Monday night meeting to replace Harman with authority deputy director Angus Olson.

"Our committee felt . . . over period of time that wearing two hats posed some difficulties," board chairman Rose Berler said yesterday. "It's a difficult thing with all the pressure of minding the city."

Although one board member said the agency had been considering the move for two months, Harman said yesterday the vote had caught him by surprise.

"I met the Friday before with Berler and I wasn't told anything about it," he said. "Now that the city work's been done, they want to go off and be independent again."

The action was the latest in a lengthy fight between the Alexandria City Council and the housing authority, which receives substantial funds from the city for urban renewal, housing subsidies and rehabilitation programs. fHarman was installed as executive director in 1977 by the council to strengthen its control over how the money was spent.

Harman said yesterday he will recommend to the council that a $1 million community development block grant fund now controlled by the housing authority be allocated by the council in the future.

"My recommendation is to allow them to be independent . . . with some understanding that all major policy and budget decisions of housing come back to the city," Harman said.