French bank Societe Generale's shares traded in Frankfurt recovered ground on Thursday after the bank's CEO sought to reassure investors that rumors that wiped 15 percent off its stock were unfounded.

The shares were 5 percent firmer at 24.80 euros by 2:49 a.m. EDT. The stock closed at 22.18 euros in Paris on Wednesday after the market battered the bank amid speculation about its financial solidity.

Rumors about a French sovereign debt downgrade, an expanded bailout for Greece that would hurt French banks and a government bailout of SocGen -- all denied -- pulled shares of France's second-largest bank down in the heaviest volume since the 2008 financial crisis.

SocGen CEO Frederic Oudea dismissed the rumors as absolutely rubbish in an interview with CNBC television after the market closed, adding rumours about a downgrade of France's sovereign debt rating were very strange and contrary to the reality of the situation.

In an interview with Le Figaro newspaper published on Thursday, Oudea said the bank had come under a series of attacks in the stock market, adding the bank had not experienced any losses in particular in the past few days and its results to date were satisfying.

The market is an echo chamber: it amplifies good news, as well as bad, Oudea told France Info radio. People are scared, so the tiniest information touches off irrational fears.

To our clients, we have to tell them that these rumors are baseless and that they can have confidence in Societe Generale. They should not listen to this stuff, which is totally baseless.

Shares in SocGen were due to start trading in Paris at 3 a.m. EDT.

(Reporting by James Regan and Leila Abboud; Editing by Dan Lalor)