La Caixa, one of the biggest and soundest Spanish savings banks, suffered a blow to its planned stock market listing later this year after Standard & Poor's lowered its credit rating. The agency said problems in the Spanish banking sector are far from over, as the domestic economy is still shrinking and funding costs remain high.

Standard & Poor's downgraded La Caixa's rating one notch to A+/A-1 from AA-/A-1+ as well as CECA and Banco Popular, as Spanish banks are likely to experience a "difficult" 2011, it said.