NEW YORK, SEPT. 28 -- Three groups from St. Petersburg, Fla., argued their cases before the National League's expansion committee today and all expressed confidence that their area would get one of the two new teams that will begin play in 1993.

Phoenix, which has had trouble putting together its bid, also made its proposal, along with a group that hopes to play a quarter of its season in four different cities. A total of 16 groups from 10 cities are seeking the two teams at $95 million each.

The National League will narrow the field to a short list by the end of the year and will pick the teams by Sept. 30, 1991.

Groups from Buffalo; Charlotte, N.C.; Denver; Miami; Nashville; Orlando, Fla.; Sacramento, Calif.; and Washington made presentations to the committee last week.

Tampa car dealer Frank Morsani, Sarasota citrus and real estate investor Thomas L. Hammons and Washington lawyer Stephen W. Porter head the three St. Petersburg groups. All would play in the 42,321-seat Florida Suncoast Dome that opened March 3.

Morsani, who owns Precision Enterprises and has been trying eight years to get a team for the Tampa area, said he would call his team the Florida Panthers. Barry Rona, former head of the baseball owners' Player Relations Committee, is a consultant to Morsani's group.

Porter was somewhat of a surprise as head of his group, especially since baseball has stressed that it wants local ownership in control of the new teams. Until today, that group had been headed by Porter's cousin, Joel Schur.

Together, the two operate the St. Petersburg Cardinals of the Class A Florida State League. The bid is being assisted by Lonn Trost of Shea & Gould, a former lawyer for the New York Yankees.

Martin Stone, who owns the Phoenix Firebirds of the Class AAA Pacific Coast League, this week merged his bid with that of the Maricopa County Sports Authority. Stone today called his earlier feuding with the municipal group "stupid."

The club that would be owned by Malcolm Glazer would be on the move constantly. His plan is to have it play at least 19 games in each of four cities, chosen from among Buffalo, Denver, Miami, St. Petersburg and Washington. He assumes the fifth city would get its own team.

He said postseason games would be split among all four cities.

"At first, people think it's a little crazy," he said of his plan, "but then they think it's a great idea. . . . The National League has problems not going to more cities. Perhaps we're the answer to their prayers."