Mitsui & Co. said Friday its U.S. subsidiary will sell its 32 percent stakes in two U.S. aluminum processing plants to Alcoa Inc., which holds 61 percent stakes in both plants, due to deteriorating profitability stemming from higher electricity costs.

Fastener maker YKK Corp. also plans to sell its 7 percent stake in each of the two plants to Alcoa, giving the world's No. 1 aluminum processor 100 percent ownership of the plants, Mitsui said.

Mitsui decided to unload the stakes because surging electricity prices in the United States made it difficult for Mitsui subsidiary Mitalco Inc. to supply power to the plants at economically reasonable levels, the trading house said.

One of the plants, located in Maryland, has been closed since January after it failed to renew an electricity supply contract when the previous contract expired. The other plant, in Washington state, is negotiating a new contract to replace the one that expires at the end of September.

Despite the selloffs, aluminum smelting will remain a core business for Mitsui and the firm plans to increase its investment in the business because global demand is likely to continue growing.