Multinational insurance holding company , Sequoia Indemnity and Personal Express Insurance (Sequoia), for nearly $60m.
Under the terms of the definitive agreement, the transaction is expected to complete after receiving regulatory approval, however no definite time has been disclosed by the firms.
AmTrust Financial Services president and CEO Barry Zyskind said that the company will continue to acquire business units similar to Sequoia to improve the profitability of its operations in niche markets.
"In addition, we believe combining organic growth with appropriate strategic acquisitions maintains attractive returns on equity and thus, improves shareholder value," Zyskind added.
Sequoia Insurance provides various low hazard property/casualty insurance products such as workers' compensation and commercial package insurance to small businesses in key western states in the US.
During 2012, the underwriter wrote gross written premium of nearly $140m.
Headquartered in New York, AmTrust Financial Services delivers specialty property and casualty insurance products, including workers' compensation, commercial automobile and general liability; extended service and warranty coverage, through its insurance carriers.