First Wind Holdings LLC, Algonquin Power and Utilities Corp. and Emera Inc. announced Saturday that they have entered into an agreement to jointly construct, own and operate wind energy projects in the Northeast.

First Wind has a 370-megawatt portfolio of wind energy projects in the Northeast, including three operating projects in Maine and another near operation.

The wind farms will become part of an operating company of which First Wind will own 51 percent. Emera and Algonquin are entering into a separate joint venture, Northeast Wind, which will own 49 percent of the operating company.

In addition to its ownership interest in the operating company, First Wind will serve as its managing partner and will continue to operate the projects.

“This is an excellent strategic partnership that brings together the region’s leading wind company with some of the region’s leading power and utilities companies,” Paul Gaynor, CEO of First Wind, said in a statement. “This agreement will support First Wind’s plans to grow and develop and invest in new projects in the Northeast and across the country.”

“This partnership brings together Algonquin’s renewable generation experience (and) Emera’s financial capacity and marketing experience with First Wind’s development expertise, and is consistent with our renewables strategy in the region,” said Chris Huskilson, president and CEO of Emera.

The First Wind projects in Maine being transferred to the operating company are Mars Hill Wind; Stetson Wind I, Danforth; Stetson Wind II, Danforth; and Rollins Wind, with expected completion in July.