The U.S. Justice Department Dec. 21 gave antitrust clearance to the merger of Exelon Corp. (NYSE: EXC) and Constellation Energy Group Inc. (NYSE: CEG), but said the companies must sell three power-generating plants in Maryland in order to proceed with the $8 billion deal.

The Wall Street Journal reports that the department said the transaction as originally proposed would have lessened competition for wholesale electricity and increased prices for consumers in the Mid-Atlantic region.

The companies reportedly agreed to sell the plants as part of a proposed settlement that was filed in a Washington federal court.

The companies still need approvals from Maryland and New York regulators, as well as the Federal Energy Regulatory Commission and the U.S. Nuclear Regulatory Commission.

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