A Merril Lynch report states that the exposure to Greece is around €200 million. However there is considerable exposure to Portugal:
The net assets of Santander’s Portuguese subsidiary, Totta, totalled €2.7bn which compares with Santander’s group equity of €74bn. Totta’s total balance sheet is around €46bn. BBVA’s Portugual operations by contrast do seem to us de minimis. CredAg and La Caixa also have minority stakes in Portuguese banks
(BES and BPI respectively).
Source: Merril Lynch