Ameresco Inc. is planning an initial public offering of up to $125 million.

The Framingham, Mass., company designs and installs measures that are meant to cut energy and maintenance costs for its customers, primarily federal, state and local governments in North America. It also builds small renewable energy plants for clients.

Ameresco said it served more than 1,000 customers in 2009.

The company said late Wednesday in a filing with the Securities and Exchange Commission that it plans to use proceeds from the IPO to pay debt, and for working capital.

Ameresco has posted a yearly profit since 2002. It earned $19.9 million in 2009, up from $18.3 million the previous year. Revenue grew to $428.5 million from $395.9 million.

Ameresco did not say how many shares it planned to sell, what price it hoped to get for them, when it planned to go public or under which symbol it would trade.

The lead underwriter is Bank of America Merrill Lynch.