Societe Generale shares traded in Frankfurt recovered some ground early on Thursday after the bank's head sought to reassure investors that a host of rumors that wiped 15 percent off its stock were unfounded.

The shares were up 5.8 percent at 25 euros at 2:06 a.m. EDT after closing at 22.18 euros in Paris on Wednesday.

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

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

(Reporting by James Regan; Editing by Leila Abboud)