Investec has maintained its 'sell' rating for UK lender Royal Bank of Scotland (RBS), recommending investors not to own the stock ahead of its third-quarter results on November 1st.Analyst Ian Gordon said that the bank will likely fall back into the red in the second half, though most of the damage will come in the fourth quarter. "Despite all the considerable 'balance sheet repair', we still believe that RBS has a dangerous cocktail of legal, political and regulatory obstacles to overcome," he said.Credit Suisse has labelled SSE and Shanks (rated 'outperform') as buying opportunities, saying that the market is overly cautious about these utility providers.Meanwhile, despite staying cautious on the UK water sector due to concerns over low returns, Credit Suisse raised its rating for water company United Utilities from 'underperform' to 'neutral', saying that the stock has lagged and now offers just 2% total return downside to the target price of 660p.IT infrastructure services firm Computacenter was trading in the red on Friday after UBS downgraded the stock from 'buy' to 'neutral'.While the bank said that the stock's valuation is not demanding, it believes the company is "navigating a tricky path in France and Germany's turnaround is at an early stage". "With July's capital return behind us, we see limited upside from current levels and move to a 'neutral' rating."BC