French power company EDF and Chinese nuclear firm CGN won regulatory approval from the EU's competition authority on Thursday to build and operate nuclear power plants at Hinkley Point in Britain.
Britain said the Hinkley Point project, one of the world's costliest, is needed to replace ageing reactors and polluting coal plants.
The European Commission said it did not see any serious competition issues.
"The Commission's investigation found that competition in the wholesale supply of electricity in the UK will not be hindered by the transaction given the moderate market share of EDF, the very limited market shares of CGN in this market and the presence of other competitors," it said in a statement.
(Reporting by Foo Yun Chee)