Australian Unity Bank scored half a rating upgrade yesterday from S&P."We are revising AUB's stand-alone credit profile (SACP) to bb+ from bbb-," the rating agency said."At the same time, we are affirming our long-term and short-term issuer credit ratings on AUB at BBB and A-2, respectively, as we believe AUB remains an important part of the Australian Unity Ltd group and its strategy."Our stable outlook on AUB reflects our expectation that AUL, AUB's ultimate parent, would provide financial support to the mutual bank, if needed, offsetting a weakening in the bank's risk-adjusted capital."S&P said it forecast its risk-adjusted capital Or RAC ratio for AUB to decline to between 13.7 per cent and 14.7 per cent through to June 2021, from 15.3 per cent as of December 2018.