A half-hearted "for sale" sign went up on the UK banking business of National Australia Bank yesterday.In a brief paragraph in its annual financials, NAB said that the group "would consider opportunities in the United Kingdom that are financially attractive."NAB was, and may still be, in talks with UK cashbox NBNK over a sale of Clydesdale Bank. But NBNK may now be concentrating on its twin bids for Northern Rock and the portfolio of Verde branches that the Lloyds Banking Group is obliged to sell.The bank's CEO and CFO made no mention of the sale options for their UK business in the investor briefing yesterday, and the long-running speculation about an NAB exit from the UK elicited no answers.What is clear about NAB's UK business is that it remains a drag on the group, just not so severe a one as before.UK Banking reported a return on assets in the September half of 0.47 per cent, an improvement of 20 basis points over 18 months.On the other hand, the business is stagnant, rather like the UK economy, which is facing weak business and consumer confidence, and public sector austerity.NAB CEO Cameron Clyne told Lateline Business last night that NAB's UK strategy was still to "grow the business organically"."Profit is up significantly from last year. Now it's still well below the returns we'd like. ""If opportunities emerge to strengthen our position through acquisition, or alternatively if we receive an attractive offer to the business, of course we consider that in the interests of our shareholders, but we're not engaging in fire sales, nor are we doing silly acquisitions just to say we've got scale."Mark Joiner, finance director of NAB, said the "sticky" charge for bad debts across the group as a whole "is now being driven out of the business bank in the UK".The bad debt charge in the UK was little changed in the second half at £145 million. Cash profit for the half was £106 million, and for the year was £183 million.Bank of New Zealand, by contrast, is earning a tidy yield, with an ROA of 1.05 per cent for the full year and 1.12 per cent for the second half, results bound to remind observant regulators that the level of bank profits in New Zealand is very high by world standards.BNZ reported cash earnings of NZ$612 million for the full year, up 17 per cent.In the United States, Great Western Bank reported an ROA of 1.17 per cent for the full year and 1.13 per cent for the second half. Full-year profit was US$90 million.A revaluation of loans from last year's takeover of TierOne trimmed the second half profit. NAB said that if that factor was ignored the second half was "marginally favourable" for GWB.