Travelers has purchased Galatea Underwriting Agencies, a specialist Lloyd's marine underwriting agency.
Galatea is in its eighth year of operation, and specialises in protecting companies and individuals who service the shipping, transport and both offshore gas and oil industries.
Travelers said Galatea "complements and enhances the current Lloyd's marine activities underwritten through St. Paul Travelers Syndicate 5000".
Galatea's managing director, Chris Childs, said: "We are very pleased with the transaction which promises continuity and security for our policyholders and brokers, with considerable potential for growth over the long term.
"Galatea's operational structure and strategy will continue unchanged and so for policyholders and brokers it will effectively be business as usual."