Power generating company Dynegy Inc. plans to buy power plants and other assets from Duke Energy Corp. and private equity firm Energy Capital Partners in two separate deals worth a combined value of $6.25 billion.

Houston-based Dynegy, which emerged from bankruptcy in 2012, is acquiring interests in 11 power plants in the Midwest from Charlotte-based Duke Energy for $2.8 billion. It will also buy the interests of 10 plants in New England, Pennsylvania and the Midwest from Energy Capital Partners for $3.45 billion; The assets acquired from Energy Capital include EquiPower Resources Corp. and Brayton Point Holdings LLC, Dynegy said.