Shares in reinsurer Transatlantic Holdings rose more than 8 percent on Monday despite broad and deep market declines, after Warren Buffett's Berkshire Hathaway made an unsolicited offer over the weekend to buy the company.

Transatlantic shares rose to $48.92 in morning trading, far outstripping a 1.1 percent decline in S&P insurance shares.

The company now has three suitors -- Berkshire, its agreed buyer Allied World and hostile candidate Validus. Transatlantic and Allied reached a deal in mid-June, which Validus attempted to trump in July with an offer it has now taken to shareholders.

At the share prices shortly after the markets opened Monday, the Allied World bid was a 7 percent discount to Transatlantic's share price, while the Validus offer is a 4 percent discount and the Berkshire offer is a 6.2 percent premium.

All three deals value Transatlantic at less than book value. Transatlantic currently trades at 0.72 times its book value, compared to a sector average of 0.74, according to Thomson Reuters data.

(Reporting by Ben Berkowitz. Editing by Robert MacMillan)

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