At least two Gulf-based banks have prepared contingency plans to raise extra capital of about $300m each to help cover writedowns of their US subprime exposure, according to Moody’s, the rating agency.

The agency has been monitoring the possible impact of subprime-related writedowns on the balance sheets of up to 10 Gulf-based banks over the past five months, said Mardig Haladjian, general manager of the financial institutions group at Moody’s in Cyprus.