Large Wall Street investment firms are moving to acquire U.S. utility companies in an effort to benefit from the rising demand for electricity from data centers. But the deals are increasingly being contested by consumer groups who say they will lead to higher energy costs for residents.

BlackRock, the world’s largest asset manager, last year proposed buying Minnesota Power, a utility that owns several power plants and thousands of miles of power lines that could help technology companies secure energy for their data centers.

But a state administrative law judge recommended late Tuesday that Minnesota utility regulators deny the proposed acquisition sought by BlackRock’s Global Infrastructure Partners division and the Canada Pension Plan Investment Board. The utility provides power to 150,000 residential and business customers, largely in northern Minnesota, including Duluth and Grand Rapids.

The acquisition appeared to be on a smoother glide path late last week when the Minnesota Department of Commerce removed its opposition to the deal and entered an agreement with the parties involved in the transaction.

The recommendation of the administrative law judge, Megan J. McKenzie, is not binding, but it could sway the Minnesota Public Utilities Commission, whose approval is necessary for the acquisition to advance.

She highlighted concerns of opponents of the deal that the investment firms would prioritize making money over ensuring reliable electricity service, potentially harming consumers.