Standard & Poor's lifted its long-term credit rating on Bank of Queensland to BBB+ from BBB. S&P affirmed the short-term rating at A-2.S&P said the upgrade reflected a revised assessment of the bank's capital and earnings position to "strong" from "adequate". S&P said it expects the bank will maintain its capital ratio in a range from 14 per cent to 15 per cent over the medium term.Three months ago, BOQ sold A$450 million in new shares, lifting its capital base by one fifth, after a surprise first-half loss of $91 million, tied to a one third rise in impaired assets.S&P said its new view "recognises… that BoQ has adequately addressed its non-performing loans… and limits the prospect that material further provisioning will be required."