Medical Malpractice Insurance Cos. Combine

Professionals Group Inc. and Medical Assurance Inc. have agreed to combine to create the nation’s third-largest medical malpractice insurance firm. The cash and stock transaction is estimated to be worth $240 million.

The companies are expected to form a holding company, Medical and Professionals Assurance Inc., which will own the stock of Medical Assurance and Professionals Group. The group has combined total premium writings of $426 million and combined medical liability premiums of $281 million, making the combined company the No. 3 writer of health-care-professional and facilities liability insurance in the country.