Moody's Investors Service said on Friday that it had cut the long term credit rating of Bank of Queensland to A3, from A2. The credit ratings agency said the outlook remained negative for the bank's rating.Moody's placed BOQ's ratings on review for possible downgrade in October. It justified its rating action on a deterioration in asset quality and ongoing structural challenges. BOQ is exposed to a number of large commercial loans, and the weakening economic environment is making resolution of these exposures difficult, according to Moody's.In addition, BOQ sources 40 per cent of its funding from wholesale debt markets, though scarcely any of this funding is from offshore. In December, Standard & Poor's cut the BOQ rating to cut to BBB from BBB+.