Fourteen years after losing a baseball team for the second time, Washington, D.C., made a new pitch to acquire a major league expansion team today, as a six-man contingent addressed Commissioner Peter Ueberroth and baseball's long-range planning committee.

By day's end, half of the 12 cities invited here had made one-hour presentations, with the rest scheduled for Friday. The D.C. group was reveling that President Reagan volunteered his support in a letter sent Wednesday to Ueberroth, writing that he looks forward "to a tradition which has long been absent from this city -- the Presidential privilege of throwing out the first ball."

Although the expansion picture in Washington became much clearer today, the overall future of expansion remained unclear.

Ed Durso, executive vice president for major league baseball and spokesman for the long-range planning committee, said, "We're not going to make any announcements, commitments or timetables today or (Friday). It's not our purpose to encourage or discourage cities, just to gather facts."

Officials from Denver, Vancouver, Indianapolis, Miami and Columbus, Ohio, as well as Washington, made presentations today. On Friday, representatives of Buffalo, Tampa/St. Petersburg, New Orleans, Phoenix, Nashville and East Rutherford, N.J., will make presentations.

It's expected that the long-range planning committee will make recommendations on expansion at baseball's annual winter meetings Dec. 9-13 in San Diego. Durso said it was possible that some cities might be asked to make a second presentation before that time.

He added that expansion and the relocation of struggling franchises, such as the San Francisco Giants, would be settled together, although the Giants' situation "is on a faster track."

D.C. Councilman Frank Smith, chairman of the D.C. Baseball Commission, said, "(Ueberroth) said that expansion and the transfer of certain (existing) teams will be on the agenda in San Diego and he said he didn't want representatives (from expansion-hopeful cities) attending because he didn't want discussions in an atmosphere where there is a lot of people running around and lobbying."

The six-member D.C. group included Smith, attorney Robert Washington, Robert Pincus (D.C. National Bank president), Andy Ockershausen (executive vice president, WMAL Radio) and developers Oliver T. Carr and James Clark, part of one of Washington's two ownership groups.

Members of the long-range planning committee would not comment on the particular presentations today.

Besides Ueberroth and league presidents Chub Feeney (National) and Bobby Brown (American), the following executives attended today's presentations:

George Steinbrenner (Yankees), Jerry Reinsdorf (White Sox), Haywood Sullivan (Red Sox), Jim Campbell (Tigers), Peter Hardy (Blue Jays) and Roy Eisenhardt (A's), representing the AL.

Charles Bronfman (Expos), John Madigan (Cubs) and John McMullen (Astros), representing the NL. Three NL executives on the committee did not attend: Peter O'Malley (Dodgers), Bill Giles (Phillies) and Nelson Doubleday (Mets).

Most significantly for Washington, the city's two potential ownership groups more clearly defined themselves and their principals today. Carr and Clark announced that their group has swelled to eight members and, Carr said, possesses "assets in excess of $500 million."

Redskins owner Jack Kent Cooke, a formidable group of one, did not attend today's meeting, although he was invited, preferring to send a letter Wednesday to Durso.

Carr said he expected his group to reach 12 members. In addition to Carr, Clark, Dr. Robert Schattner and developers Robert Smith and Ted Lerner, three previously undisclosed investors were named: Louis Byron (president of McGregor Printing Corp.), Melvyn Estrin (chairman of the board of Human Service Group, Inc.) and Sheldon Fantle (chairman of People's Drug, Inc.).

Bowie Kuhn, former baseball commissioner, has been affiliated with this group. Though the meetings took place at the law firm of Wilkie, Farr and Gallagher, which employs Kuhn, the former commissioner did not appear at today's presentation. Kuhn was unavailable for comment.

Though sources indicate that distance has developed between Kuhn and the group, Carr said, "We will negotiate with Bowie, and we, with him, will determine whether or not there is a role he will play in the future."

Carr said his group would offer "stability" and added, "We offer a broader community representation, and we offer a diversity that probably is not found in a single ownership. In our community, we think that is right."

Carr said that the group of owners will elect each year a managing general partner "who will run the day-to-day operations." He added that plans call for no majority owner.

Cooke, in his letter, noted his 34 years of sports management and said he could offer a "continuity of ownership" that would shift control of the team, over time, from Cooke to his son John (currently Redskins executive vice president) and then, Cooke suggested, to his grandson, John Kent Cooke Jr.

"Rumor has it that baseball may opt for a group or a syndicate of owners in preference to a single owner," Cooke wrote. "I find this hard to credit, bringing to mind, as it does, CBS's disastrous ownership and management of the New York Yankees. A sole proprietorship, I submit, produces solid results for a sports team."

Carr said, "The difference between us is that we are a group and he is an individual . . . Our resources as a group are probably quite close (to Cooke's, recently estimated by Forbes magazine to be about $600 million).

"We do feel that we have adequate resources to properly finance the operation . . . of a fine baseball team," Carr said.

Asked if Cooke might join the group in the future, Carr said, "That's up to Mr. Cooke. We invited him to join our group, but he declined. I don't know what more we can do." (Cooke declined to comment.)

"I would imagine (baseball executives) still look at Mr. Cooke as a potential owner," said Pincus. "However, Mr. Carr and Mr. Clark being here was a very positive step in terms of their ability to be recognized as a leading group."

Members of the D.C. group said the long-range planning committee expressed two concerns about Washington: the location of RFK Stadium and the possibilities of securing a favorable lease for a potential team.

Pincus said, "A lot of that was the perception that goes back to the '60s when someone characterized Washington as the crime capital of the world, and we have certainly changed that perception. We impressed upon them that the stadium was secure, would be modernized and, with the network of highways and Metro, that it was very convenient to the citizens of the metropolitan area."

Jim Dalrymple, general manager of RFK Stadium, who attended today's meeting as a technical advisor, said it was impressed upon baseball executives that, once the title to RFK Stadium is transferred from the Department of Interior to the District government (which is expected to occur shortly), the city will "make every attempt" to negotiate a favorable lease with a baseball team.

The Redskins are the sole tenant of the stadium; their lease expires in 1990. Dalrymple said, however, that the current lease (signed in 1960 when Washington had a baseball team) specifies that baseball will be the primary tenant. Thus, if an expansion team was awarded to Washington for the 1987 season, it would become the primary tenant.