ZURICH, Switzerland--As the new chief executive officer of Swiss Reinsurance Co. takes over, his key challenge will be steering the reinsurer closer to its traditional business model while maintaining its image as an innovative provider of risk-financing solutions, analysts say.

Jacques Aigrain tendered his resignation earlier this month after Swiss Re's preliminary announcement that it expects a loss of 1 billion Swiss francs ($876.2 million) for 2008 and said it would raise 3 billion Swiss francs ($2.60 billion) from Warren Buffett's Berkshire Hathaway Inc. to bolster its surplus capital. Swiss Re formally reports its earnings Feb. 19.

Stefan Lippe, the Zurich-based reinsurer's deputy chief executive officer and chief operating officer, was named to succeed Mr. Aigrain.

Analysts say the writing was on the wall for Mr. Aigrain, given the size of Swiss Re's losses.

"It was expected that Mr. Aigrain would step down sooner or later," said Georg Marti, an equity analyst with Zürcher Kantonalbank in Zurich.

"There had been a lot of pressure on his position in recent months," said an analyst who asked not to be named.

Swiss Re clients, investors and brokers now are focused on how Mr. Lippe will attempt to steer the reinsurer out of its financial difficulties.

"For the time being, it will be very tough for the new CEO to change the business," said Mr. Marti. "The risk exposure is still there and he has to manage it somehow."

Mr. Lippe's appointment "is certainly a positive development in light of the situation at Swiss Re and how the market views the company," said Neal Enriquez, an analyst with Oldwick, N.J.-based A.M. Best Co. Inc.

"He is a 25-year veteran and a home-grown, traditional reinsurance underwriter, and I believe that is the direction the company is going to go," Mr. Enriquez said.

Swiss Re has been looking to revert to a more traditional business model and Mr. Lippe's appointment could accelerate that move, said the analyst who asked not to be identified.

The analyst pointed out, however, that Swiss Re would be ill-advised to focus entirely on its core reinsurance business at the expense of all other less traditional operations.

The company was, for example, seen as a market leader in transforming insurance risk into capital-market products. "We viewed that positively," the analyst said, and such initiatives that have had positive long-term benefits for the reinsurer probably should not be abandoned.

Mr. Lippe's more than two decades with Swiss Re have included positions such as CEO of the reinsurer's Bavarian Re Group. In 2001, he was appointed head of Swiss Re's worldwide property/casualty business and in 2005 was named to lead property/casualty and life and health underwriting.