Brief: ProAssurance posts Q1 gross premiums USD 315.794 million
May 9 (Reuters) - ProAssurance Q1 adjusted operating income USD -8.071 million. * Q1 pretax profit USD -8.346 million * Q1 net income USD -6.174 million * Q1 operating expenses USD 67.788 million * Q1 gross premiums USD 315.794 million