The warning by the Basel Committee last week that banks will have to face lower returns in future has not dissuaded Deutsche Bank from extolling the virtues of investing in the shares of UK banks Barclays, Lloyds Banking and Royal Bank of Scotland.The German bank has reiterated its 'buy' recommendations for all three, believing that an improvement in the loan write-down situation is on the way in the second half of next year.Deutsche concedes, however, that the market may continue to treat the shares with suspicion until the next results season in February. The banks also remain vulnerable to a slump in confidence which could bump up funding costs.