Investec has recommended investors to 'sell' shares of global banking giant HSBC, downgrading the stock from 'hold' after a "very disappointing" set of annual results last month.The broker said that it sees limited value across the whole UK banking sector and advised against adding to position in any listed lender.In spite of the weak results, which were some 33% below consensus, HSBC's UK shares have rebounded 10% over the past month."HSBC is also quoted on the Hang Seng index (which helps!) and it owns 19.3% of Bank of Communications (itself trading at a four-year high)," said analyst Ian Gordon."We do continue to believe that HSBC's generous payout is sustainable. However, when the dust settles, we think investors will see RoE>CoE as merely a 2018 aspiration and act accordingly. 'Sell'," he said.In the aftermath of the full-year results, Gordon cuts his target price on the stock to 570p from 630p and reduced pre-tax forecasts by 16% to £19.9bn for 2015 and by 13% to £22.5bn for 2016."According to Bloomberg data, our revised earnings per share forecasts of $0.69, $0.78 and $0.84 through 2015-17 are 17%, 8% and 7% below consensus," he said.The shares were down 0.1% at 617.46p by 10:41 on Tuesday.