Altamont Capital Partners has agreed to purchase Topa Insurance Group from its owner Topa Equities for an undisclosed sum.

Following completion of the transaction, Altamont will assume majority control of the acquired entity while Topa Equities will maintain a minority equity stake.

Established in 1981, Topa operates as the holding company of property and casualty (P&C) insurance carrier Topa Insurance Company, and Dorchester Insurance Company, the second-largest P&C carrier in the US Virgin Islands.

Last year, it wrote more than $130m in gross premium across its internally-managed wholesale channel and third-party managing general agency partners.

Altamont Capital said that the strategy for the business will remain largely unchanged in terms of a focus on specialty P&C lines after completion of the transaction.

Altamont principal Sam Gaynor said: “We are strong proponents of the specialty P&C insurance business and believe that Topa has built a phenomenal platform in the space. We are looking forward to bringing our resources to bear in partnering with Topa’s management team to further build on its franchise and expand into related lines of coverage.”

Altamont managing director Keoni Schwartz said: “Topa represents our 7th insurance platform investment at Altamont and, including add-on and pending transactions, 19th overall insurance acquisition at Altamont.

“Topa will serve as our foundational specialty P&C insurance carrier business in the US and we believe our expertise in the space will drive numerous opportunities for growth over the coming years.”

The transaction is subject to regulatory approvals as well as satisfaction of customary closing conditions.