NEW YORK (Reuters) - Insurer Ace Ltd. said yesterday it expects to earn between $7.25 and $8.25 per share next year, the midpoint of which is below the average expected by analysts.

The company also expects $415 million in pre-tax catastrophe losses, and said it was operating in "a period of great uncertainty".

"Global economic and financial conditions will be difficult for the foreseeable future," Ace chief executive officer Evan Greenberg said. "On the other hand, commercial property and casualty market conditions are in a state of change and this presents opportunity for Ace," he said.

The midpoint of Ace's 2009 earnings estimate is $7.75, below the average of $7.90 expected by analysts polled by Reuters Estimates.

Shares of Zurich-based Ace rose 76 cents (1.5 percent) to close on $51.76 in New York Stock Exchange trading yesterday.