Switzerland-based insurer Swiss Re said on Thursday that its net profit rose by 61 percent in 2012 to $4.2 billion (3.2 billion euros), outpacing market forecasts, despite the impact of Hurricane Sandy.

"In dollars, these are the highest results ever reported by the group," Swiss Re's chief financial officer, George Quinn, told reporters.

The figures were driven by a 15-percent increase in premium revenues, which reached $25.4 billion, as well improved profitability in its damage insurance business, Swiss Re said.

Analysts polled by Swiss financial newswire AWP had predicted net profit of $3.5 billion, and premiums of $24.6 billion.

In mid-morning trading, the group's shares rose by 1.83 percent to 75.15 Swiss francs ($81.48, 60.87 euros), while Switzerland's SMI index was down 1.10 percent overall.

Swiss Re's combined ratio -- a measure of an insurer's effectiveness, setting management costs and claims payouts against premiums -- was 83.1 percent in 2012.

The group had been expecting a worse ratio of 94 percent.

Swiss Re maintained its forecast that it will have to pay out around $900 million in claims stemming from damage done by Hurricane Sandy to the east coast of the United States in October.

Insurers had seen payouts spiral in 2011 in the wake of the tsunami disaster in Japan and floods in Australia.

For 2013, Swiss Re said it was expecting rapid premium growth, thanks in part to the expiry of a so-called retrocession contract with US billionaire Warren Buffet's investment fund Berkshire Hathaway.

At the height of the financial crisis, Swiss Re ceded 20 percent of its premium volume to Berkshire Hathaway.

The contract ran out at the end of 2012, and has not been renewed.

Buffett, however, is seeking between $500 million and $1.0 billion in damages related to Swiss Re's US life insurance business.

Pressed on the issue, Swiss Re's chief executive Michel Lies declined to elaborate.

"We have nothing new to tell you on this. We are still in discussion regarding these retrocessions," he told reporters.

Swiss Re's board has proposed a 2012 dividend of 3.50 Swiss francs per share, up from 3.0 Swiss francs for 2011.

The group marks its 150th anniversary this year, and said it would add a one-off dividend of 4.0 Swiss francs per share.

Market-watchers underlined that the dividend was well ahead of expectations.

"The 7.50 Swiss franc result is a dividend yield of 10.2 percent, clearly an attraction in the current low rate environment," said Helvea analyst Daniel Bischof.