AM Best Co. has assigned a debt rating of bbb to the recently issued $300 million 5.5 percent senior unsecured notes due 2020 of Allied World Assurance Company Holdings Ltd.

The assigned outlook is stable.

Best said that the proceeds from the debt offering will be used for general corporate purposes., with the debt-to-adjusted capital ratio and fixed charge coverage remaining comfortably within the range that is commensurate with the assigned rating.

The ratings agency added that Allied World was a diversified property/casualty insurer/reinsurer with significant geographic reach, with strong risk-adjusted capitalisation, an experienced management team and a historically strong operating performance.