...TORONTO (S&P Global Ratings) Oct. 30, 2017--S&P Global Ratings today said it has assigned its '###' debt rating to Markel Corp.'s (###/Stable) proposed issuance of senior unsecured notes due in 2027 and 2047 reflecting the issuer credit rating on Markel Corp. The company will use the proceeds of this offering for general corporate purposes. On a pro forma basis, as of third-quarter 2017, we expect the issuance to increase Markel's financial leverage to about 26.4% (around 24.3% as of Dec. 31, 2016) before improving slightly to about 25% by 2019. At the same time, the fixed-charge coverage for 2017 will be about 2.0x (including the impact from catastrophe losses) and will improve to 4.0x-6.0x for 2018-2019 assuming normalized earnings. These metrics are in line with our expectations and supportive of the ratings. In our analysis of risk-adjusted capitalization, we allow for only 20% of debt-funded double leverage. As a result, proceeds in excess of this threshold will not be included in...