MOVING MOUNTAINS

White Mountains Insurance Group agreed to buy the U.S. property/casualty operations of British insurer CGNU Group for $2.1 billion. The Hanover, N.H-based insurer is also expected to pay $500 million in debt owed by the U.S. unit to its parent group. Warren Buffett of Berkshire Hathaway will invest up to $300 million in convertible shares of White Mountains as part of the deal’s financing. CGU’s home office will remain in Boston and White Mountains’ Chairman and CEO Jack Byrne is expected to join the CGU holding company’s board as its chairman. The unit will also be adopting a new company name as the U.K. parent company retains the CGU moniker.