Colorado power company Xcel Energy (XEL) will purchase two Denver-based power plants from competitor Calpine Corp. (CPN) for $739 million. 

Together, the plants power around 700,000 households in the state.

The plants being sold are a 621-megawatt facility known as the Rocky Mountain Energy Center and a 310-megawatt facility called the Blue Spruce Energy Center. 

Shares of both companies were modestly higher on Monday.