NEW YORK (Reuters) – Ace Ltd gave a 2010 earnings outlook below Wall Street estimates yesterday, and the insurer's shares fell 2.4 percent.

The Zurich-based property-casualty insurer, which has its oeprating headquarters in Bermuda, forecast operating income of $6.25 to $6.75 per share for this year. On average, analysts expected $7.64, according to Thomson Reuters I/B/E/S.

Hexagon analyst David Havens said the announcement was a "modest" negative for Ace, but not surprising given the outlook for lower insurance pricing in 2010.

"Watch out for other P&C insurers to follow suit in terms of providing better-than-dour, but less-than-rosy profit outlooks," said Havens.

Ace said the outlook might not be comparable with some analysts' estimates. It includes estimated pretax catastrophe losses of $390 million, but not any estimate for the potential release of reserves previously set aside to cover claims.

Operating earnings exclude some investment losses and gains.

The company's shares were off $1.20 or 2.44 percent at $48.07 in afternoon New York Stock Exchange trading.

Ace estimated catastrophe losses included in its projected earnings would be $317 million after-tax.