White Mountains Insurance Group Ltd. has agreed to pay $751 million in cash and two runoff property-casualty businesses for the White Mountains shares now owned by Berkshire Hathaway Inc.

Berkshire Hathaway, Omaha, Neb., owns about 16% of the stock of White Mountains, Hamilton, Bermuda, according to White Mountains.

White Mountains and Berkshire Hathaway have both been major investors in Symetra Financial Corp., Bellevue, Wash., a life insurer that was spun off from Safeco Corp., Seattle, in 2004.

The two insurance companies Berkshire Hathaway will be getting are Commercial Casualty Insurance Company, Los Angeles, and International American Group Inc., Wilmington, Del.

Commercial Casualty and International American ended 2007 with about $435 million in combined assets, White Mountains says.

The deal has a total value of $836 million, White Mountains estimates.

White Mountains is making the deal to get out of runoff businesses, redeploy capital, and buy back stock at a price close to book value, according to White Mountains Chief Executive Ray Barrette.

Berkshire Hathaway helped White Mountains finance a major property-casualty acquisition in 2001, and now White Mountains competes in many markets against Berkshire Hathaway, Barrette says.

“This is a graceful, value-enhancing way to go our separate ways,” Barrette says.

The deal has been approved by the White Mountains board and is subject to approval by regulators, White Mountains reports.