White Mountains Insurance Group

White Mountains Insurance Group (NYSE: WTM) is a holding company with business interests in property and casualty insurance, and reinsurance. The group owns reinsurer Sirius and a 75% stake in specialty insurance carrier OneBeacon. It is based in Hanover, New Hampshire.

It is owned by Jack Byrne who in 1985 was invited to run the troubled Fireman's Fund, then a subsidiary of American Express. Fireman's had incurred $356 million in pretax losses in 1983 and 1984. Byrne greatly improved Fireman's financial performance and initiated a public offering of some of Fireman's shares in 1985. The company was sold to Allianz AG in 1991. Byrne, meanwhile, retained the Fireman's holding company, which he later renamed White Mountains.

White Mountains Insurance Group, Ltd. (White Mountains or the Company) is a financial services holding company with primary business interests in property and casualty insurance and reinsurance. The Company's corporate headquarters and its registered office are located in Hamilton, Bermuda and its principal executive office is located in Hanover, New Hampshire.

The Company conducts its principal businesses through:

• Sirius Group - global reinsurance.
• OneBeacon - specialty insurance. OneBeacon's common shares are listed on the New York Stock Exchange under the symbol "OB". White Mountains holds a 75% interest in OneBeacon as of 12/31/11.
• White Mountains Advisors - investment management with $34 billion of assets under management as of 12/31/11.

White Mountains' common shares are listed on the New York Stock Exchange and the Bermuda Stock Exchange under the symbol "WTM". Market capitalization as of December 31, 2011 was approximately $3.4 billion.

As of December 31, 2011, White Mountains reported total assets of $14.1 billion, adjusted shareholders equity of $4.1 billion, and Adjusted Book Value per Share of $542.