The Fortune 500's biggest losers

After forcing out CEO Gary Forsee in the fourth quarter of last year, the No. 3 U.S. wireless carrier acknowledged what the market long suspected about how bad the Nextel merger was by writing off $30 billion related to that 2005 acquisition.

The Nextel network, based on the slower iDEN technology rather than CDMA or GSM, lost 2.8 million subscribers in 2007 and revenue-per-user fell throughout the year. Overall, Sprint Nextel gained wireless users, but a price war with Verizon and AT&T led to lower operating earnings. New CEO Daniel Hesse hopes big bets on unlimited service contracts and a national WiMAX network will help stop the bleeding.

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