Foreign banks are well in the black, reporting the kind of profit margins last seen before the global financial crisis.Quarterly data on bank performance produced by the Australian Prudential Regulation Authority shows foreign branch banks earned a profit margin of 28.1 per cent in the June 2013 quarter.Aggregate net profit for the 40 foreign branch banks was A$323 million, the highest since the APRA data-set started in 2004.A steady improvement in asset quality has helped lift profits. The ratio of impaired facilities to loans and advances is now 1.4 per cent, the lowest since the GFC.