Swiss Re's shares had climbed to 96.95 Swiss francs in Zurich trading on April 13, the highest since 2007, fueled by special dividends and a planned buyback of stock worth as much as 1 billion francs ($1.1 billion). The shares fell 0.7% to 82.7 at 12:29 p.m. on Thursday, extending losses since the high to 14%.

Investment Return

Return on investments increased to 3.9% from 3.7% a year ago, driven by the sales of fixed income securities. The reinsurer booked net realized gains of $380 million after $234 million in the year-earlier quarter. Lower revenue from equities and alternatives pushed down income from investments to $728 million from $835 million a year ago.

"The improvement in profit all seems to come from one-offs from selling fixed income securities and movements in hedges," said Charles Graham, an analyst at Bloomberg Intelligence in London.

Earnings at the life and health reinsurance unit increased to $277 million from $64 million a year ago, driven by income from selling securities and foreign exchange re-measurement. Losses from an interest rate hedge last year also weren't repeated, the company said.

Swiss Re's Admin Re unit, which buys and manages closed books of life and health insurance, increased net income to $206 million from $48 million.

"This will not be the new run rate" for Admin Re as the unit's net income was supported by realized gains from the sale of government bonds, Chief Financial Officer David Cole said.

Profit at the property and casualty reinsurance division declined 18 percent to $808 million as prices fell.

Return on Equity

Swiss Re's return on equity improved to 16.1% in the quarter from 14.9% a year ago.

"Mid-term, we see Swiss Re developing into a lower ROE group, as its highest ROE (P&C Re) segment has started to shrink," Thomas Seidl, an analyst at Sanford C. Bernstein in London, said in an e-mailed report to clients.

The rates property and casualty reinsurers charge primary carriers to backstop claims from catastrophes declined in seven of the last 10 years, according to the Guy Carpenter World Property Catastrophe Rate on Line Index.

"We were probably able to outperform most of our peers on pricing," Swiss Re CFO Cole said, referring to April renewals, where the company renegotiates about 10 percent of its property and casualty reinsurance treaty portfolio. "The market as a whole saw a continued albeit moderated softening."