The Chicago-based media conglomerate controlled by Sam Zell is considering offers from three groups of investors and could make a decision within 10 days, the Chicago Tribune reported Tuesday.

Sources close to the negotiations say any sale still could derail and the team and Wrigley Field be taken off the market, especially since tight credit markets will make it more difficult to obtain financing that could run as high as $1 billion, the newspaper reported.

The three prospective buyers are Chicago investor Hersch Klaff; the Ricketts family, founders of TD Ameritrade Holding Corp. (NASDAQ:AMTD); and a group of investors led by Marc Utay, a New York private-equity investor who grew up in Chicago.

Tribune Co. filed for Chapter 11 protection in December. The Cubs are not included in the filing, but their sale would generate money for debt-holders.