GDF Suez said the acquisition is in line with the strategy of developing its Cofely brand in energy services.
Ecova provides solutions for utility expense and data management, energy supply, facility optimization and energy efficiency via a smart data management platform.
Ecova, which helps its clients manage their energy consumption costs, employs over 1,450 people in 18 offices throughout North America.
The company, which serves over 700,000 clients sites, generated $180m of revenues in 2013.
GDF Suez executive vice president in charge of energy services Jérôme Tolot said the acquisition is a major step for the company in energy efficiency.
"It will reinforce our expertise in energy data management and combined with our multi-technical know-how in energy efficiency. We will be able to offer innovative and concrete services to assist our clients with the transition to a low carbon economy," Tolot added.
Avista said it anticipates to use most of the proceeds to buy back stock, subject to board approval, and business investment.
The transaction is anticipated to be completed by 1 July 2014.
