The European banking sector does not need another round of stress tests because the exposure of large banks to sovereign debt is already public, Société Générale Chairman and CEO Frédéric Oudéa told CNBC Tuesday. 

"The exposure to sovereign debts is public. They are well known," Oudéa said. "Markets can make calculations and I think generally speaking, people totally overestimate the impact of any kind of scenario on this sovereign debt."