US-based ratings agency A.M. best has placed under review the financial strength rating of A (Excellent) and the long-term issuer credit rating of “a+” of Sompo Japan Canopius Reinsurance AG (Switzerland).

The credit rating announcement follows the successful completion of SOMPO Holdings, Inc. acquisition of Endurance Specialty Holdings Ltd. on 28 March this year, for a total consideration of US$ 6.3bn.

The agency its rating action reflects “uncertainties” over Sompo Japan Canopius Reinsurance AG’s future business profile and its strategic importance within the Sompo group.

Sompo Japan Canopius Reinsurance AG was incorporated in Switzerland on 23 November 2015, following the redomiciliation of Canopius Reinsurance Limited from Bermuda. The company underwrites third-party reinsurance business through a network of branches in Switzerland, Bermuda, and prospectively, the US and Singapore.

A.M. Best expects property and casualty reinsurance to contribute the majority of Sompo Japan Canopius Reinsurance AG’s reported gross revenues in 2016.

The ratings agency said it will continue to monitor the impact of the transaction on Sompo Japan Canopius Reinsurance AG’s business profile and its strategic role within the Sompo group, and expects to resolve the under review status when additional details on the company’s future business plans become available.