Reuters reported that bids were submitted by groups led by Tom Ricketts, chief executive of Chicago investment bank Incapital LLC; Marc Utay, a managing partner with New York-based private-equity firm Clarion Capital Partners LLC; and Chicago real estate executive Hersh Klaff.
The Cubs had no comment on the bids.
Dallas Mavericks owner Mark Cuban apparently has not submitted a bid. Cuban was charged by federal regulators with insider trading last month and has not been part of the bidding for months, according to Reuters' sources.
Monday's round of bids came after the groups had received more detailed financial data on the Cubs, Wrigley Field, and a 25-percent stake in a regional sports TV network. The bidders had met with executives from Major League Baseball.
The Tribune Co. put the Cubs on the block on Opening Day in April 2007 when it announced it would be bought for $8.2 billion by a group led by real estate magnate Sam Zell. Analysts have said the team and other assets could attract bids topping $1 billion. But the sale has been delayed, and the country's economic situation has led to speculation that final bids could be lower than expected.
There also have been reports that Tribune Co. could retain a stake of as much as 50 percent in the club to help complete a deal.
Carrie Muskat is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.