The Bank of Spain has fined Banco Santander SA €6.4 million and Unicaja Banco SA €1.50 million for breaching banking regulations, the central bank said May 17.

Santander was fined for two "serious infringements" on information provided in contracts and on the calculation of interest rates. Unicaja was fined for one"serious infringement" for the same thing and "very serious infringement" on charging fees for a bank document.

Spanish banks have been sharply criticized by consumer groups for mistreating customers, and the country has seen several mis-selling scandals.