As Philadelphia worried yesterday about losing its National Football League franchise, Pittsburgh Mayor Richard S. Caliguiri called for a city-wide effort to keep the baseball Pirates in his city, saying three firms would provide free legal, accounting and public relations services to new owners who promised not to move the team.

"If you can tell me what more we can do, short of myself buying the team, I'll do that," Caliguiri said.

The mayor said the Price-Waterhouse accounting firm, the Ketchum Communications Inc. public relations and advertising firm, and the Eckert, Semans, Cherin & Mellot law firm would contribute about $1 million in services to a buyer willing to keep the Pirates in Pittsburgh.

Fears about the Pirates' future arose last month when the John Galbreath family of Columbus, Ohio, the Pirates' principal owner since 1946, said it and partner Warner Communications would sell the team following a last-place season that cost them $6 million.

Pittsburgh and Philadelphia weren't the only areas contemplating the loss of professional sports teams. The New York Daily News reported yesterday that officials from two baseball teams, the San Francisco Giants and the Cleveland Indians, have been talking to members of the New Jersey Sports and Exposition Authority, with the Garden State's representatives using the promise of a new stadium exclusively for baseball as a lure.

Duffy Jennings of the Giants said owner Bob Lurie would prefer to sell to someone who would keep the team on the West Coast, and Lurie denied talking to anybody from New Jersey; Bob DiBiasio of the Indians said Steve O'Neill, owner of the team until his death last year, had a clause in his will that the Indians must stay in Cleveland for at least 15 years.

And in Baton Rouge, La., Gov. Edwin Edwards, passed on a purchase offer to John Mecom Jr., owner of the NFL's New Orleans Saints, in an effort to keep that team in his state. The proposal involves the wealthy Pritzker family of Chicago, and some Louisiana businessmen may get involved, Edwards said.