France's biggest retail bank Credit Agricole made a loss in the last three months of 2007, hit by a hefty charge at its Calyon investment banking arm.
Credit Agricole sponsors a successful cycling team
Credit Agricole lost 857m euros ($1.3bn, £657m) in the fourth quarter, after Calyon took a 3.3bn-euro charge on losses related to the credit crisis.
That charge is worse than Credit Agricole's forecast in December of a 2.5bn-euro loss.
The bank also dismissed rumours that it might bid for Societe Generale.
Societe Generale has been seen as a takeover targest since it announced huge trading losses in January.
It blamed a former trader, Jerome Kerviel, for placing unauthorised trades that lost the company 4.9bn euros ($7bn; £3.7bn).
Like many other big banks, Credit Agricole has reported losses on assets backed by US mortgages.
Many of those home loans were granted to borrowers with poor credit histories and are known as sub-prime mortgages.
More and more of those homeowners are failing to meet their payments, resulting in severe losses for banks owning those assets.