European competition regulators announced on Monday that they have closed a year-long probe into a deal between French and German nuclear giants Areva and Siemens.
The European Commission said it had made "legally binding" commitments offered by the companies to limit areas where they had agreed contractual "non-compete" clauses.
"The Commission had concerns that the non-compete obligation might prevent competition, in breach of EU antitrust rules," said a statement.
"After market testing the commitments offered by Siemens and Areva, the Commission is satisfied that they address its concerns and has closed its investigation."
Areva and Siemens came together in this area in 2001 with a joint venture, Areva NP, that was cleared by the commission with the subsequent acquisition of sole control by Areva also cleared in 2009, Brussels said.