Two prominent Washington area groups and an Indianapolis-based media executive have emerged as the front-runners in the bidding to become the new owners of the Washington Nationals because of the support they have within Major League Baseball, according to sources with intimate knowledge of the sale.

The top candidates include a Washington-based syndicate headed by businessmen Fredrick V. Malek and Jeffrey Zients; the Lerner family, which runs a Bethesda-based real estate empire; and Jeffrey Smulyan, founder and chairman of an Indianapolis-based media conglomerate, the sources said.

The timing of baseball's announcement on the sale remains unclear. The league initially said it hoped to have a new owner selected by midsummer, but it has repeatedly pushed back the announcement as it held multiple meetings with representatives of all eight groups that put in bids for the team.

However, the sources with knowledge of the process, who spoke on condition of anonymity, said Commissioner Bud Selig and his close advisers are focusing on the two Washington area groups and Smulyan.

The sources cautioned that Selig has said that none of the eight groups has been eliminated. They added that since the decision ultimately is Selig's alone to make, they are hesitant to rule out any bidder or to handicap the front-runners.

Chicago White Sox owner Jerry Reinsdorf, who is representing baseball in talks with the District on the Nationals' lease of a new baseball stadium, said last week that a decision is unlikely until November, or at least until the White Sox are eliminated from the playoffs. Some members of the D.C. Council are seeking to review the lease agreement, which baseball officials say must be completed before a new owner can be selected.

"I know it's taking a long time," Selig told reporters in Chicago on Tuesday. "No one is more sensitive to this than I am."

A further complication emerged yesterday when Natwar M. Gandhi, the city's chief financial officer, said the stadium financing deal must go back to the council for technical amendments. It prompted concerns that some council members will seek to renegotiate the carefully crafted deal with Major League Baseball that brought the sport back to Washington.

One factor in baseball's decision is what one source called Selig's "comfort level" with the new owners. The commissioner is expected to meet with Malek and Zients, and with members of the Lerner family as early as next week, one senior baseball official said. The official said Selig would meet with other groups as well, including those who aren't considered front-runners. The Lerner family is headed by Theodore "Ted" Lerner, his son Mark and his two sons-in law. Selig already knows Smulyan, the former owner of the Seattle Mariners. Selig declined through a spokesman to comment for this story.

District officials, including Mayor Anthony A. Williams, have made it clear that they favor local ownership of the Nationals, and some members of the D.C. Council have warned that selection of an outside owner could negatively affect support for construction of a new stadium for the team on the Anacostia waterfront. Baseball, which has owned the Nationals franchise since 2002, selected Washington as the site of the team last year based on Washington's commitment to build the $535 million stadium project.

Some top baseball officials are known to favor the Malek-Zients and Lerner groups over Smulyan because both Malek and Zients and Lerner have longtime ties to Washington and thus, they believe, would have more local political backing. Williams has publicly expressed support for Malek-Zients, and sources said political allies of the Malek-Zients group have lobbied Selig on its behalf. Malek was one of the leaders of the campaign to bring baseball back to Washington.

Some baseball insiders support Lerner because the team would be owned by a family with deep financial resources and with close ties to the community. The Lerner group also has appeal with baseball because the Lerners don't have a long list of investors, as does Malek-Zients and Smulyan, that could complicate the management of the team.

Smulyan, as a former owner, is backed by some in the baseball hierarchy, reportedly including Reinsdorf. After his name emerged as a contender in recent weeks, Smulyan made a high-profile visit to the District and announced the addition of several prominent Washington area individuals to his group, including Eric Holder, former U.S. attorney for the District, and former Redskins Art Monk, Charles Mann and Calvin Hill.

A second tier of possible owners is led by Franklin Haney, a businessman with offices and residences in the District and in Tennessee, the sources familiar with the sale process said. After Haney, a Northern Virginia-based group of businessmen led by Albert Lord, chairman of Sallie Mae, and William Collins has some support inside baseball. Stan Kasten, former president of the Atlanta Braves, is considered a long shot, according to the sources.

Two other bidders, one led by Washington entrepreneur Jonathan Ledecky that includes billionaire George Soros, and another group composed of Chicago businessman Yusef Jackson -- son of the Rev. Jesse Jackson -- and grocery store billionaire Ronald Burkle, have not garnered as much support as the others, the sources said.

Baseball has set a $450 million price on the team. Most groups indicated they were willing to meet that price tag when nonbinding bids were submitted to baseball last month.

Baseball President Bob DuPuy last month said a sale would not be completed until the city signs a lease agreement with the league that sets the rent and other conditions under which the Nationals will use the new riverfront stadium in Southeast. The stadium is scheduled to open in March 2008. Reinsdorf, who has been negotiating the lease with D.C. Sports & Entertainment Commissioner Mark Tuohey, said Tuesday that the lease issue was delaying a decision on the ownership.

"They want certain things in the lease, certain things which are not worth mentioning publicly," he said. "That's what's holding it up. But it will happen, sooner or later."

Staff writer Dave Sheinin contributed to this report from Anaheim, Calif.