Charter Oak Financial, MassMutual Greater Long Island and MassMutual Greater Hudson have merged their operations.

The combined firm will operate as Charter Oak Financial and will be led by managing partners Brendan Naughton and Brad Somma.

Charter Oak, which provides risk management, retirement and investment planning, and business services, now includes 375 advisers and a team of over 100 specialists and staff in offices across Connecticut, Massachusetts and New York.

The local firms are sales offices of Massachusetts Mutual Life Insurance Co. and are not subsidiaries or its affiliated companies.