S&P Global Ratings has placed AMP Bank's single A long-term and A-1 short-term issuer and issue credit ratings on "CreditWatch with negative implications". The agency said it has also placed its credit rating for AMP Bank's 'A-' subordinated issue on the same footing.The CreditWatch placement for AMP Bank follows similar action on the parent company AMP Ltd and its insurance subsidiaries, as well as AMP Group Holdings Ltd, an intermediate holding company of the broader AMP group. "[This action] reflects our view of risks to AMP's creditworthiness following fallout from recent disclosures that has damaged its brand and reputation, raised questions over management and governance, and seen key management and its board chair depart the group," the S&P report on AMP's main advice business explained."As a result of the Royal Commission into Misconduct in the Banking, Superannuation and Financial Services Industry, AMP disclosed that it had misled the corporate regulator, the Australian Securities and Investments Commission, in relation to its advice business having charged customers fees for services that have not been provided. "The disclosures indicated behavior outside of our previously assessed expectation for AMP's risk management culture."S&P is view the AMP group's prospective competitive position as at risk of weakening following the damage to its brand and reputation. That is, the group's market position and operating performance could be impacted should retail and wholesale customers vote with their funds under management following the debacle uncovered by the Royal Commission. The saving grace, at least at this stage for AMP is its "otherwise very strong business and financial position, including very strong capitalisation and improving earnings profile, [which] have averted any immediate lowering of its credit ratings ahead of our further review under this CreditWatch action," said S&P.In a way, it's almost a case of collateral damage for AGH, a small subsidiary of AMP that  provides a guarantee covering the senior unsecured obligations of AMP Bank. "When assessing group support for the bank, we take the higher of explicit or implicit support," the S&P analysts wrote. "The explicit support from AGHL is currently one notch higher than the theoretical rating derived from our expectations of implicit support--a function of the bank's stand- alone credit profile (SACP) of 'bbb-' and three notches of uplift above its SACP due to its strategic importance to  the broader group (collectively resulting in a rating outcome of 'A-'). "Therefore, we currently equalise our long-term and short-term issuer credit ratings, and senior unsecured issue ratings, on the bank with those on AGHL. "The subordinated issue credit rating is also on CreditWatch with negative implications, despite not being covered by AGHL's guarantee, as we notch these off the issuer credit rating on the bank.S&P said it would "resolve the CreditWatch on AMP Bank" following a similar resolution on the broader AMP group."If we were to lower the ratings on AGHL by one notch, we would expect to lower our issuer and issue credit ratings on the bank by one notch. Similarly, if we were to resolve the