ZURICH (Reuters)—Swiss Re Ltd. tripled its profit in 2011 despite unusually severe natural disasters, and said it was raising its dividend and that the current year had started well with a rise in prices.

Swiss Re said renewal prices with insurance company clients had, on average, risen 4% in January, compared with the 2% seen by larger rival Munich Reinsurance Co.

"We expect to see prices continuing to firm in the course of 2012," Swiss Re Chief Financial Officer George Quinn said on Thursday.

Swiss Re recorded a full-year profit of $2.63 billion, compared with an estimate of $1.79 billion in a Reuters poll and after seeing $863 million in profit in 2010.

Profit was helped by a good investment result, a low tax rate due to corporate restructuring, a rise of nearly 11% in property/casualty premium income, and a release of $1.3 billion of reserves.

Asset management saw a 5.1% return on investments.

"The result was exceptional and not one I would expect asset management to repeat in 2012," said Mr. Quinn. He also said the group would likely not be able to benefit from the exceptionally low 2011 tax rate this year.

Swiss Re will consider a special dividend at the end of 2012 if it does not deploy it to other uses, such as for growing its core reinsurance business, Mr. Quinn said.

The company has already paid back a convertible loan it had to take from Warren Buffett after risky bets soured during the financial crisis, and it also achieved its goal of reclaiming its former good credit rating.

Last year proved one of the costliest for insurers due, in part, to catastrophes in Japan and New Zealand.

The Zurich-based firm recorded natural catastrophe claims of $3.5 billlion—nearly three times what it expected. The bill from floods in Thailand, which hit suppliers to companies like Toyota, came in at $680 million, with the Japanese earthquake at $1.19 billion.

At the end of last year, the firm had minimal exposure to eurozone peripheral sovereign debt, which has proved a headache for some of Swiss Re's competitors.