According to Forbes, Kasten's group has the leading current bid of $1.6 billion, funded primarily by Guggenheim Partners chief executive officer Mark Walter. Kasten previously ran the Atlanta Braves and Washington Nationals, as well as the Atlanta Hawks of the NBA and Atlanta Thrashers of the NHL.
The remaining bidders are being interviewed this week in Phoenix by two Major League Baseball owners committees and then will be voted upon by the full membership of owners.
According to Forbes, the groups remaining besides Kasten/Johnson/Guggenheim are hedge-fund manager Steve Cohen and agent Arn Tellem; St. Louis Rams owner Stan Kroenke; Shamrock's Stanley Gold; and Memphis Grizzlies owner Michael Heisley and Los Angeles investor Tony Ressler.
Los Angeles real-estate investor Alan Casden has been eliminated by Major League Baseball, according to the Los Angeles Times, and New York media investor Leo Hindery is also out, according to Forbes.
Final bids are believed to be due by Friday, with current owner Frank McCourt selecting the winning bid by April 1 and the deal closing by April 30, the day McCourt must pay former wife Jamie McCourt a $131 million divorce settlement.
Ken Gurnick is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.