Bermuda-based Omega Specialty Insurance Company Ltd’s ratings have been put under review with negative implications by AM Best Europe over concerns about the group’s exposure management.The company, which has a financial strength rating of A- (excellent) and issuer credit rating (ICR) of “a-” made a pre-tax loss for 2010 of $42.9 million on high catastrophe-related claims.Best said the financial strength rating of A (excellent) and ICR of “a+” of Lloyd’s Syndicate 958, which is managed by Omega Underwriting Agents Ltd, remain unchanged at the Lloyd’s market level.Best said the 2010 loss was “a materially weaker performance than that expected”.As a consequence of the loss, consolidated risk-adjusted capitalisation has deteriorated to a level below that previously anticipated, although it remained excellent at year-end 2010.Best said it was continuing to discuss its concerns with Omega’s management team.Outstanding issues relate to the group’s risk management processes, the level of uncertainty in respect of the group’s exposure to catastrophe events in 2011 to date and the ongoing placement of the 2011 reinsurance programme, said the ratings agency. Additional uncertainty is introduced by the review by the group’s directors of approaches that may lead to an offer to acquire Omega, said Best.Best expects to resolve the under review status following a more extensive analysis of catastrophe losses in the first quarter of 2011 and the impact of recent management actions on the group’s prospective risk-adjusted capitalisation and risk management standards, in particular those relating to exposure management.