White Mountains Insurance Group Ltd has commenced a "modified Dutch auction" self-tender offer to purchase up to $500 million in value of its common shares, at a purchase price between $1,250 and $1,400 per share, in cash, less any applicable withholding taxes and without interest.

The tender offer commenced yesterday and will expire at midnight, New York City time, at the end of the day on September 20, 2022, unless extended.

White Mountains's common shares closed on the New York Stock Exchange at $1,305.13 per share on August 19, 2022.

A "modified Dutch auction" self-tender offer allows shareholders to indicate how many shares and at what price within the company's specified range they wish to tender their shares.

Based on the number of shares tendered and the prices specified by the tendering shareholders, the company will determine the lowest purchase price per share within the range that will enable it to purchase $500 million in value of shares, or if a lesser value of shares is properly tendered, all shares that have been properly tendered and not properly withdrawn.

In the event that shares representing more than $500 million in value are properly tendered in the tender offer, the company reserves the right to increase the number of shares sought in the tender offer by an amount not exceeding two per cent of outstanding shares without extending the expiration time for the tender offer.

All shares purchased by the company in the tender offer will be purchased at the same price regardless of whether the shareholder tendered at a lower price.

D.F. King & Co Inc are serving as information agent for the tender offer. The dealer managers for the tender offer are J.P. Morgan Securities LLC and Barclays Capital Inc.