ZURICH (Bloomberg) ? Swiss reinsurer Converium Holding AG yesterday agreed to sell its North American operations to Warren Buffett?s Berkshire Hathaway Inc. for $95 million to help restore its credit rating.

Berkshire Hathaway will also assume $200 million in debt, Zug, Switzerland-based Converium said. The company said that it isn?t providing Omaha, Nebraska-based Berkshire any guarantee or indemnity regarding the North American operations? reserves.

?We are pleasantly surprised by the price achieved,? Brian Shea, an analyst at Merrill Lynch in London, said in a research note. Now, ?Converium must settle its SEC investigation? to be able to get a higher credit rating.

Inga Beale, the reinsurer?s third chief executive since the start of 2005, has pushed for a sale of the North American operations as she aims to regain the ?A? rating needed to win new contracts. Converium?s shares lost over half their value in three days in July 2004 after it reported an unexpected $660 million loss, triggered by a reserve shortfall in the US.

Berkshire Hathaway?s National Indemnity Company will assume all of the North American operations? reinsurance liabilities, worth $1.06 billion as of June 30, said Converium, which was spun off from Zurich Financial Services and has a Bermuda subsidiary. The company estimates the sale will lower shareholders? equity by $135 million.

?With this transaction, we have successfully delivered on our promise? to exit North America, Beale said in a statement. ?We can now fully concentrate on building Converium?s future, with our business strategy focused on markets outside the US.?

Converium shares closed at 15.90 Swiss francs in Zurich, down 0.3 percent, reversing earlier gains of as much as 2.8 percent. They?ve risen 18 percent since Dec. 21, the day before Swiss financier Martin Ebner announced the purchase of a stake in the reinsurer. Ebner told the Swiss weekly SonntagsZeitung in March that he plans to as much as triple his investment should the company?s credit rating be raised.

Ralph Stadler, a spokesman for Patinex AG, the investment company through which Ebner bought his Converium stake, declined to comment today on whether Ebner would buy more shares.

Standard & Poor?s plans to issue a response to the planned sale today, analyst Rowena Potter said in London, without giving details. In addition to a sale of the North American operations, the rating company wants to see ?some kind of closure? of the regulatory investigations in the US, she said.

Standard & Poor?s in August said it may increase its ?BBB+? financial strength rating on the Swiss reinsurer after a sale. Reinsurers help insurers such as Allianz AG shoulder risk.

Regaining an `A? rating will allow Converium to resume underwriting in markets such as the UK and Australia, executive vice president Frank Schaar said last month.