Banking stocks were mostly under the weather on Friday with domestic lenders Royal Bank of Scotland and Barclays leading to the downside.RBS was being weighed down by some gloomy comments from Investec analyst Ian Gordon, who recommended investors not to own the stock ahead of the bank's third-quarter results on November 1st.The 17% fall in first-half 'core' pre-tax profit to £2.5bn was entirely due to a sharply lower contribution from the Markets division. Gordon said that there will likely be "no relief" in Markets in the third 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, as he retained his 'sell' rating and 345p target price. RBS was down 1.1% at 372.8p in afternoon trade.Barclays, meanwhile, was dampened by reports of another probe into allegations of more LIBOR-rigging.Guardian Care Homes (GCH) is suing Barclays over interest-rate swaps, claiming the bank mis-sold it inappropriate interest rate hedging products based on LIBOR that ended up costing it millions of pounds as rates fell.Barclays denies mis-selling and says the LIBOR-rigging allegations are irrelevant to the dispute. The bank is asking the Court of Appeal to overturn an earlier ruling that GCH could amend its claim to include LIBOR-related allegations.The Financial Conduct Authority has said it has "no current plans" to launch another probe into Barclays. However, that didn't stop the share price falling 0.6% to 276.65p.Sector peers HSBC and Lloyds were also out of favour on Friday, a day after Exane BNP Paribas speculated that UK banks may need to raise as much as £100bn more capital to meet regulatory requirements. The Prudential Regulation Authority (PRA), due to make its final statement in December, could introduce additional capital buffers on top of current regulation, Exane said. Quite simply, if the PRA adopts its proposals in full we believe the UK banks will need to have fully loaded equity tier-1 ratios of at least 13% over time." Nevertheless, analysts believe that Lloyds (rated 'outperform') is the only UK bank that is likely to reach a 13% fully loaded equity ratio by 2015.Top performing sectors so far todayHousehold Goods & Home Construction 10,502.61 +1.79%Life Insurance 6,673.40 +1.67%Oil Equipment, Services & Distribution 24,055.51 +1.65%Electricity 9,275.15 +1.34%Chemicals 9,968.56 +1.14%Bottom performing sectors so far todayConstruction & Materials 4,261.53 -0.68%Banks 4,935.05 -0.39%Forestry & Paper 11,762.32 -0.36%Aerospace and Defence 5,010.58 -0.34%Tobacco 36,578.21 -0.25%BC