AM Best has put the ratings of Bermuda’s Arden Reinsurance and Arden Holdings under review with negative implications.The rating actions follow the recent announcement that Arden has entered into a definitive agreement with Enstar Group for the acquisition of its Arden Re company.In a statement AM Best said it placed under review with negative implications the financial strength rating of A-(Excellent) and issuer credit rating (ICR) of “a-” of Arden Reinsurance Company Ltd (Arden Re) and the ICR of “bbb-” of the parent company, Arden Holdings, Ltd (Arden Holdings) (both domiciled in Bermuda).Enstar is to purchase Arden Re for approximately $79.6 million. The transaction is anticipated to close by the end of the fourth quarter subject to regulatory approval.The ratings will remain under review pending the completion of the transaction and AM Best’s review of the future business plan and capitalisation of Arden Re, the agency said.AM Best said the rating of A (Excellent) and issuer credit rating of “a+” of Lloyd’s Syndicate 609 (United Kingdom) remained unchanged following the recent announcement that Enstar and Arden have entered into a definitive agreement under which Enstar will acquire Atrium Underwriting Group.Atrium is a wholly owned subsidiary of Arden Holdings.Atrium owns Atrium Underwriters, which is the managing agent for Lloyd’s Syndicate 609 and Atrium 5 Limited, a Lloyd’s corporate member that provides a share of syndicate 609’s capital.The ratings of syndicate 609 are underpinned by the financial strength of the Lloyd’s market and are unaffected by the acquisition. For the 2013 year of account, Atrium 5 Limited provides 25% of syndicate 609’s capacity. The remaining capacity is provided by third party capital providers, largely traditional Lloyd’s names.