Carrefour chairman Luc Vandevelde has resigned from the supermarket giant as speculation about a takeover swirled.
Mr Vandevelde was previously chairman of Marks & Spencer
Helping fan bid rumours was the news that French billionaire Bernard Arnault and private equity group Colony Capital had bought a 9.1% stake in Carrefour.
Mr Vandevelde's future had been in doubt amid rumours of disagreements with the Carrefour's most powerful shareholder, the Halley family.
He will be replaced by Robert Halley, whose family owns 13% of Carrefour.
Mr Vandevelde was previously chairman of British retail icon Marks & Spencer, and was once nicknamed "Lucky Luc" by UK analysts.
However, he quit in 2004 - citing personal commitments to the Halley family - after failing to achieve a sustained turnaround in the UK company's then troubled fortunes.
M&S has since been revived under current chief executive Stuart Rose.
Carrefour is second only to US retail giant Wal-Mart
Analysts said Mr Vandervelde's position had been weakened following his recent departure from the holding company of the Halley family, which controls 26% of shareholder voting rights.
A share purchase by Mr Vandevelde in February triggered speculation that the world's second biggest retailer was considering a leveraged buyout, which would expose Carrefour to higher debt levels.
The company of billionaire Bernard Arnault said its stake in Carrefour was "a strategic, industrial and long-term investment".
"Colony Capital and Groupe Arnault consider that Carrefour, a world leader in its sector, has strong potential for growth," it added.
Together with investment group Axon Capital, Groupe Arnault said the combined consortium now controlled 9.8% of Carrefour stock.
Under French laws, investors must declare their shareholding intentions once a threshold of 10% has been breached.