The subprime mortgage-led credit crisis yesterday forced the first bailout of one of the specialist insurance groups that write guarantees for debt issuers when two leading French banks pledged $1.5bn to support the credit ratings of CIFG.

Caisse d'Epargne and Banque Populaire, two mutual banks, will buy the bond insurer from Natixis - the French investment bank that itself is controlled by the two mutuals - and then inject the $1.5bn to enable it to maintain its AAA rating.