Alexandria Mayor Frank Mann said yesterday that he and some friends are attempting to purchase a AAA minor league baseball club for $1 million to play at Alexandria George Washington Secondary School next spring.

Mann would not say what AAA franchise his group is trying to buy, saying it would be premature to do so since some major league clubs will be expanding their farm teams and others are changing their major league affiliations.

He also did not want to disclose who was joining him in the venture except to say. "They're personal friends, mostly people in the Grandstand Managers Club who have assured me they will back me in purchasing and promoting the club and selling stock and other things."

Mann said that AAA baseball officials have sent a representative to examine Alexandria's suitability and that three parent teams are thinking about placing a minor league club in Alexandria.

Baseball commissioner Bowie Kuhn has committed himself to returning major league baseball to Washington's RFK Stadium. Sources in both the American and National leagues have said recently that Washington's chances for a big-league club have increased for next spring, with speculation centering on the Oakland A's moving here.

Because of this. Mann's proposal was not greeted with widespread enthusiasm by some members of the Grandstand Managers Club, to whom he revealed the plan Tuesday night.

Mann insisted his plan would not kill Washington's chances for a major league team. But he added that he doubts major league baseball will return here.

Mann said there is "more than one site in the city" that could accommodate a AAA club, but that George Washington Secondary School, located at 1005 Mt. Vernon Ave., is considered the best.

The city, he added, has already "formally committed itself to putting in more parking, seats and a dugout" at the 7,500-seat stadium. Mann said he expects the renovations would cost "a couple of hundred thousand dollars."

"I hope the city will back me in putting the high school in first-class condition," Mann said. The City Council has not yet approved any appropriation.

He said the team would not cost the taxpayers anything in the long run since the city could rent the property to his group. Mann predicted the club would return a profit.

The mayor said he expects his group could buy a AAA franchise for "about $1 million." Eventually, he added, the franchise would be financed by the sale of stock. Only residents of the metropolitan area would be allowed to purchase the stock and the amount would be limited so that one person could not control the franchise