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Investors in these Fortune 500 companies saw handsome returns in 2011.

1. El Paso
1. El Paso
Fortune 500 rank: 488
2011 revenue: $4.9 billion
2011 total shareholder return: 93.6%
Ticker: EP

A takeover and a huge bet on the future of natural gas sent El Paso shares surging last year. In October 2011, Kinder Morgan struck a $21.1 billion deal to buy El Paso. The sale, which was approved by shareholders and is expected to be finalized later this year, combines the two biggest natural gas pipeline operators in North America, making it the continent's fourth-largest energy company.

The stock also rallied earlier in May when El Paso announced plans to split the company, dividing its exploration and production business from its pipeline operations. Needless to say, those plans have been shelved. In February, El Paso agreed to sell its exploration and production business for approximately $7.15 billion to affiliates of Apollo Global Management LLC and Riverstone Holdings LLC who are joined by Access Industries and other parties.

By Nin-Hai Tseng @FortuneMagazine - Last updated May 07 2012: 10:52 AM ET
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