A group formed recently to bring a major league baseball team to the District of Columbia has begun lobbying club owners and Commissioner Bud Selig, trying to convince them that a Washington team would not have a significant, detrimental financial impact on the Baltimore Orioles.

"We've embarked on a mission, contacting and writing the owners, seeing as many owners as we can, to make the case for Washington," one member of the new group, lawyer Steve Porter, said yesterday during a lunch with Washington Post reporters and editors.

"We've got a fight," said lawyer Paul Wolff, another member of the group. ". . . We're going to convince [Selig and the owners] that there's a certain tradition in baseball that requires the nation's pastime to be in the nation's capital. Baseball is a tradition-laden sport."

Though no team is for sale, the Montreal Expos may be sold if a new ownership group isn't formed in the next several weeks. The new six-man D.C. group, known as Washington Baseball Club LLC, would compete for the right to purchase the Expos against groups in Charlotte and Northern Virginia. D.C. businessman Douglas Jemal also is involved in the effort.

The Washington group is led by Fred Malek, a Nixon White House advisor and former Texas Rangers part-owner who heads Thayer Capital Partners, a District-based investment firm that manages several billion dollars and owns the city's largest hotel, the 1,463-room Marriott Wardman Park.

The other investors are Jim Kimsey, founding chief executive officer and chairman emeritus of America Online Inc.; Franklin D. Raines, chairman and chief executive officer of Fannie Mae; and Joe Robert Jr., chairman and chief executive officer of J.E. Robert Companies, an Alexandria-based investment and asset management firm.

Porter said members of the D.C. group have written letters and begun making phone calls to all but one of the 30 major league club owners. Orioles owner Peter Angelos, who has said he would strongly oppose a team being awarded to Washington, has not been contacted, Porter said. Angelos has said 25 percent of his club's tickets are sold to Washington area fans.

"Mr. Angelos's estimates of how much he depends upon the Washington market for his [ticket] sales are terribly inflated," said Porter, a partner at the District's Arnold & Porter law firm.

Wolff said his group has commissioned a study of the financial impact a D.C. team would have on the Orioles. He declined to disclose who is doing the study.

"We are trying to find out statistically: Is there an argument that baseball is going to suffer from having major league play in the District of Columbia?" said Wolff, a partner at the District's Williams & Connolly law firm. ". . . We're trying to see if people can in a fairly scientific manner [conclude whether a Washington team] is a plus for Major League Baseball, that there will be more fans, more revenues, more TV, more radio, more sponsorships and . . . two very strong teams" -- in Washington and Baltimore.

Porter estimated that Angelos could possibly lose between $4 million and $6 million a year in gross ticket revenues if a big league team played in the District.

"That's almost inconsequential to the operation of the club," Porter said, adding that Angelos would "just have to run his club a little more efficiently."

Porter said Selig raised the Baltimore issue in a recent conversation.

"I know it's on his mind," Porter said. "It's a legitimate question. We think that he's been given a tremendous amount of misinformation over the years, particularly since Camden Yards was built. And we recognize it's our job to come up with better information."

Meanwhile, the Washington group has hired an architect -- David Schwartz, who designed the Ballpark in Arlington, Tex. -- to recommend how RFK Stadium could be renovated, according to Wolff.

Wolff said a Washington team would likely play its first four or five seasons at RFK. He said that while a new downtown stadium would be considered, the team could end up at RFK. "We have a stadium that we think can have around 35,000 first-rate seats," he said.

Washington hasn't had a major league baseball team since the Senators left RFK to become the Texas Rangers in 1971.