The firm’s decision to join the MISO follows a move by Entergy in April 2011 to integrate its transmission systems in the states of Arkansas, Louisiana, Mississippi and Texas into the Midwest power grid.

Entergy hopes to fully join the MISO and complete the ITC transaction by the end of 2013. Joining MISO would help Entergy’s customers and save $1.4bn in the first decade, reports Reuters.

The power grid operator has a developed power market that is expected produce benefits for customers through enhanced reliability and efficient power supply, Cleco said.

Cleco president and chief executive Bruce Williamson said, "As our market structure changes, Cleco is positioned well to participate in MISO, known for the value it creates for its members and their customers through strict market oversight."

"Cleco’s fleet is environmentally sound, well maintained and should perform well under MISO’s operating guidelines."

The MISO operates the power system in 11 states of US Midwest and the Canadian province of Manitoba.