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3. Sprint Nextel
3. Sprint Nextel
Fortune 500 rank: 85
2010 loss: $3.5 billion

The outlook seemed brighter for the wireless carrier at the end of 2010 as it managed to add postpaid subscribers during the fourth quarter for the first time since 2007. For the year, it lost a net of 855,000 postpaid customers, but that's a significant improvement over the 3.5 million prior year loss.

The progress in Sprint Nextel's customer retention wasn't enough to keep the company from reporting its fourth annual loss in a row. The carrier noted in its annual report that the net loss of its postpaid customer segment in the past two years means wireless service revenue in 2011 could be about $2.4 billion less than if Sprint had kept those subscribers. The company is also still hurting from its troubled acquisition of Nextel in 2005.

And news that AT&T plans to buy T-Mobile only puts Sprint farther behind its two larger rivals.

NEXT: 4. Energy Future Holdings
Last updated May 05 2011: 3:06 PM ET
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