The U.S. Nuclear Regulatory Commission on Friday cleared the transfer of operating licenses for Constellation Energy Group Inc. (CEG) nuclear-power plants to the joint venture created by the purchase of half the company's nuclear business by Electricite de France SA (EDF.FR).

Completion of the $4.5 billion deal, struck in December, has been delayed pending various regulatory approvals. Once completed, EDF would own 49.99% of the nuclear business, with Baltimore-based Constellation owning the remaining 50.01% through two intermediate companies.

The NRC placed several conditions on the deal, including requiring that at least half the board members of the nuclear company, Constellation Energy Nuclear Group, be U.S. citizens. NRC rules prohibit nuclear licenses from being owned, controlled or dominated by a foreign individual or company. The nuclear unit's chief executive, chief nuclear officer and chairman of the board must also be U.S. citizens, the NRC said in a press release.

"EDF's investment in Constellation Energy's nuclear assets represents a unique opportunity to deliver significant economic, energy and environmental benefits to a broad array of stakeholders and would be a powerful catalyst for new nuclear development in the United States," EDF and Constellation executives said in a statement. EDF and Constellation have plans to build new reactors at the Calvert Cliffs nuclear power plant in Maryland.

Constellation agreed to the EDF deal in December, spurning an offer from Warren Buffett's MidAmerican Energy Holdings Co. that would have taken the company private. Baltimore-based Constellation was facing the possibility of filing for bankruptcy protection.

The EDF deal is still awaiting approval from Maryland regulators, who last week gave interveners in the case extra time to file testimony. Constellation is appealing a Maryland Public Service Commission decision that gives state regulators authority to block the deal.

Maryland regulators are concerned that the deal would affect Constellation's utility, Baltimore Gas & Electric.

The NRC's approval of the agreement with EDF was widely expected and isn't likely to speed up the review process in Maryland, said Angie Storozynski, an analyst with Macquarie Securities in New York.

"Nobody was expecting delays with the NRC approval," Storozynski said. "It was a given."

-By Mark Long and Christine Buurma, Dow Jones Newswires; 212-416-2145; mark.long@dowjones.com