AM Best, the credit ratings agency, has placed the ratings of Bermudian-based Aspen Insurance Holdings Ltd and its subsidiaries under review with positive implications, following news of a $3.5 billion takeover by Sompo Holdings.

Aspen, which has major operations in Bermuda, the United Kingdom and the United States, agreed earlier this week to be acquired in full by Sompo, a global insurance group headquartered in Japan. The deal remains subject to regulatory approval.

AM Best said the review reflects the potential benefits Aspen could gain from joining a much larger organisation with greater financial strength. “The ratings will remain under review pending completion of the transaction and a detailed review by AM Best of Aspen’s future business plans,” the agency said.

Ratings placed under review include Aspen Bermuda Ltd, Aspen Insurance UK Ltd and Aspen’s American subsidiaries, all of which currently carry an “A” (Excellent) financial strength rating. Aspen’s holding company, registered in Bermuda, carries a long-term issuer credit rating of “bbb” (Good).

Aspen preference shares and debt instruments were also placed under review.