Europe is challenging Bermuda among reinsurers considering startups or changing their domicile, a rating agency said in a report released Wednesday.

While the United States continues to be a vitally important market for reinsurance, Bermuda and Europe are vying “for the top spot among reinsurers that are launching their businesses or considering a change of address,” Standard & Poor's Corp. said.

“From the mid- to late 1990s through 2007, Bermuda was the location of choice for reinsurers that were setting up new businesses,” Laline Carvalho, a credit analyst at S&P in New York, said in a statement accompanying the report.

“Startup activity on the island was particularly strong in 2001 to 2002 following the Sept. 11, 2001, terrorist attacks, as well as in 2005 to 2006 after Hurricanes Katrina, Rita, and Wilma,” Ms. Carvalho said.

Bermuda was attractive for reinsurance startups with its relatively quick regulatory approval process, favorable taxes and proximity to the United States. But in recent years, there has been a significant shift of reinsurers moving to Europe—especially those offering insurance and reinsurance, according to the report.

Changes in taxation and regulations elsewhere in the world are prompting renewed interest in Europe as a domicile, with particular interest in Switzerland and Ireland, according to the report.

Historically, Europe has had a large reinsurance company presence. Today, five of the world's six largest reinsurers are based in the region.

In 2009, Europe accounted for 60% of global net reinsurance premiums written.

The report is available to subscribers at www.globalcreditportal.com and www.ratingsdirect.com.