French retail giant Carrefour is expected to announce today [Thursday] the resignation of chairman and chief executive Daniel Bernard after 12 years in the job.

According to The Financial Times, Bernard is set to be replaced as chairman by Luc Vandevelde, a former boss at UK retailer Marks and Spencer.

The move follows increased speculation that key shareholders are unhappy with Bernard's performance amid weak sales at the company's core hypermarkets.

Joel Saveuse, the company's director in charge of Europe, is also expected to resign.

Vandevelde joined the Carrefour board in March 2004 to represent the Halley family of shareholders. He is believed to have called for the departure of Saveuse, as well as the separation of the chairman and chief executive roles, reported The Financial Times.