Standard & Poor's held steady its credit ratings for six Spanish banks, including La Caixa, Bankinter and Sabadell, on Monday amid concern about the strength of the Spanish financial sector. 'We have reviewed all financial institutions we rate whose banking businesses are mostly concentrated in Spain,' the agency said in a statement. 'In light of the above mentioned factors, we affirmed the counterparty credit ratings of six of the seven institutions reviewed.' The announcement followed market tension last week over rumours of possible strains within the Spanish banking system. 