Redomestication away from Bermuda is having little operational impact on insurers who have chosen to move, according to credit rating agency Standard & Poor's.

Laline Carvalho, director of S&P's financial services ratings group, told BNamericas that organisational changes were typically minimal.

"It is worth noting that most of these companies are already global players, with subsidiaries and representative offices in many different locations around the world," Ms Carvalho said.

"In most cases, the fact that these companies are redomiciling to Switzerland or Ireland does not fundamentally change their business strategy, products offered, or even where most of their staff or operating subsidiaries are located."

They are for the most part simply creating an ultimate holding company based in these other countries, with the rest of the organisational structure typically remaining the same, she added.

Bermuda has a long-standing reputation of being the domicile of choice for reinsurers mainly due to favourable tax laws, proximity to the US and the relatively quick approval for starting operations. However, proposed regulatory and taxation-related changes in different parts of the world are sparking a renewed interest in European countries — especially Switzerland and Ireland.

Earlier this month, Allied World announced it plans to move its corporate operations from Bermuda to Switzerland, a trend that began in 2008 when Ace redomiciled from the Cayman Islands to Zurich, the Swiss financial capital.

XL Capital moved its domicile from the Cayman Islands to Dublin earlier this year, and in May Flagstone Re switched to Luxembourg from Bermuda, while British insurer Amlin redomesticated its Bermuda-based reinsurance unit to Switzerland.

All those companies have maintained operations in Bermuda.