The Federal Trade Commission on May 22 granted early termination of the Hart-Scott-Rodino Act waiting period for RWE AG to acquire a 16.67% stake in E.ON SE.

The acquisition is part of a complex €40 billion asset swap that involves RWE selling its 76.8% stake in innogy SE in exchange for an interest in E.ON, including E.ON's renewable energy generation assets. Both companies are currently involved in the U.K. electricity and gas markets, with RWE involved in power generation and E.ON a retail supplier, prompting a U.K. regulatory review.

The U.K. Competition and Markets Authority approved the deal on April 8.

RWE's acquisitions were approved by the European Commission regulator under a separate merger inquiry Feb. 26. Meanwhile, the European regulator is still probing the final part of the deal, which will see E.ON absorb the remainder of Innogy's distribution and retail businesses.