AUGUSTA, Maine — PPL Corp. announced Monday that it has completed an $81 million deal to sell six Maine dams to another firm.

Under the terms of the deal first announced in July, PPL will sell its stake in the dams the company now operates at Milford, Orono, Stillwater, Ellsworth, Medway and West Enfield.

The company purchasing the dams, Black Bear Hydro Partners LLC, is a subsidiary of Boston-based ArcLight Capital Partners, which has a stake in energy generation, transmission and infrastructure throughout the United States and Europe.

Black Bear Hydro Partners already owns a 50 percent stake in the West Enfield facility. Collectively, the six dams produce 36 megawatts of hydropower.

Officials have said in the past that the sale would not affect power production at the dams and that staff working at the facilities will remain on the job.

The deal involving the six dams also is not expected to affect the separate sale of three other PPL dams along the Penobscot River that is part of a historic river restoration agreement.

A coalition working together as the Penobscot River Restoration Trust is awaiting state and federal regulatory approval of plans to purchase the Veazie, Great Works and Howland dams from PPL.

The trust plans to remove the Veazie and Great Works dams and build a state-of-the-art fish bypass around the Howland dam, thereby reopening nearly 1,000 miles of watershed to Atlantic salmon, shad, alewives and other sea-run fish. As part of the deal, PPL was allowed to offset the loss of the three dams by increasing power generation at the facilities sold Monday.

“PPL believes strongly in this important project and remains fully committed to obtaining all approvals necessary to transfer these three facilities to the trust,” William Spence, PPL’s executive vice president and chief operating officer, said in a statement.

PPL said it is selling the six dams to Black Bear Hydro because the facilities are outside of the company’s core areas in the mid-Atlantic and the Northwest. Based in Allentown, Pa., PPL controls or owns more than 12,000 megawatts of generating capacity in the U.S.

ArcLight Capital Partners, the parent company of Black Bear Hydro, manages more than $6.8 billion in energy investments, according to the company’s Web site.