Icahn Invests Big in Anadarko (NYSE: APC), NRG Energy (NYSE:NRG)

Carl Icahn is back in the energy sector game, as he acquired a large number of shares in Anadarko Petroleum Corp. (NYSE:APC) and NRG Energy (NYSE:NRG), according to a required regulatory filing.

The billionaire investor bought 2.4 million shares of NRG Energy, and 2 million shares of Anadarko Petroleum last quarter.

Since last year in the same quarter, which Icahn had held no stake in energy companies at the time, has added over $900 million shares in several energy firms since then.

This isn't the first time Icahn has shown an interest in Anadarko, as in 2007 and 2008 he acquired a large stake in the company, which generated rumors he was going to shake things up there, as he has at other companies he's invested in in the past.

Anadarko owns a 25 percent stake in the same oil well which BP (NYSE:BP) had battle to contain and has billions in liabilities toward.