Companion Life Insurance has purchased International Specialty Underwriters, a managing general underwriter of stop loss coverage for employer health plans.

The acquisition includes International Specialty Underwriters’s (ISU) headquarters in Jacksonville and its other offices located in Fountain Hills, Arizona, and Edina, Minneapolis. Terms of the purchase were not disclosed. ISU has 21 full- and part-time employees, and estimated annualized premiums of $35 million.

ISU will retain its name and continue to operate independently, with its core management team in place under the current managing general underwriter (MGU) model. John Wilbur will continue serving as president of ISU.

Trescott Hinton, president of Companion Life, said: The acquisition of ISU is a natural extension of our business model and an excellent strategic fit. We look forward to significant growth opportunities. This acquisition, along with our November 2007 purchase of Montgomery Management, demonstrates our commitment and desire to continue in this market under the MGU model.