PARIS, May 10 (Reuters) - French Energy Minister Segolene Royal said on Tuesday she is investigating legal means to ban the import of shale gas from the United States because France has banned shale gas exploration using hydraulic fracking for environmental reasons.

Royal, answering a question in parliament, said contracts signed by French gas utility Engie and power utility EDF with a U.S. producer have led to the import of LNG which contained about 40 percent shale gas.

“I have asked the two companies why they weren’t vigilant and I have also asked for an examination of a legal means for us to ban the import of shale gas,” Royal said in parliament. (Reporting by Bate Felix, editing by Geert De Clercq)