Following a review of Markel Corp. and Alterra Capital Holdings Ltd. under our revised insurance criteria, we are affirming our 'A' financial strength rating on Alterra and its core subsidiaries, as well as the issue ratings on Markel and Alterra. The ratings reflect our view that Markel and Alterra maintain strong business and financial risk profiles based on their geographic and business-line diversification and very strong capital and earnings, offset by their moderate risk position. The stable outlook reflects our view that Markel's competitive position, capital and earnings, financial flexibility, and ERM will be stronger as a result of the recent Alterra acquisition. On May 22, 2013, Standard&Poor's Ratings Services affirmed its 'A' financial strength rating on Markel
