By William Horobin 

PARIS--French finance minister Michel Sapin and the head of the country's central bank François Villeroy de Galhau Monday raised concerns about the merger of London Stock Exchange Group PLC and Germany's Deutsche Börse AG.

Mr. Sapin said the merger, which would create Europe's biggest stock exchange operator, could curtail competition and create extra risk. He repeated his call for European authorities and other local supervisors to scrutinize the deal.

"We've been in a process of decreasing risks. If there is too much concentration, risks would increase," Mr. Sapin said.

The European Union in 2012 blocked a proposed merger of Deutsche Börse and NYSE Euronext.

Speaking alongside Mr. Sapin, Mr. Villeroy de Galhau warned against the creation of a large clearing house.

"It could create an operator that is too big to fail," Mr. Villeroy de Galhau said.

Write to William Horobin at William.Horobin@wsj.com

(END) Dow Jones Newswires

May 30, 2016 05:54 ET (09:54 GMT)