Following Barclays's 16 per cent drop yesterday after it was found to have manipulated interbank lending rates, shares were swinging between gains and losses today after the Financial Services Authority (FSA) revealed it has found "serious failings" in the way lenders sold complicated interest rate protection products to businesses. Some businesses claim they have been bankrupted by the liabilities they took on when entering the so-called "swap" arrangements. Yesterday's news prompted calls for the resignation of Barclays CEO Bob Diamond and today's developments will have further dented confidence in the British lender. Oriel Securities downgraded its rating for Barclays this morning to 'hold'. Heading the other way were sector peers Lloyds, HSBC and RBS who were making gains this morning as they pulled back after yesterday's sharp falls. Mining stocks were putting in decent performances as commodities prices rallied on the back of the EU summit. Vedanta, Antofagasta, Rio Tinto, ENRC and Kazakhmys were all among the best performers. Telecoms giant Vodafone was lower after Jefferies downgraded its rating on the stock from 'buy' to 'hold', highlighting threats from competitor fightbacks and this company's dependence on Verizon Wireless. FTSE 100 - RisersCRH (CRH) 1,232.00p +7.32%Evraz (EVR) 257.50p +6.85%Vedanta Resources (VED) 925.00p +6.14%Hammerson (HMSO) 451.60p +5.34%Weir Group (WEIR) 1,524.00p +5.10%Kazakhmys (KAZ) 721.50p +5.10%Hargreaves Lansdown (HL.) 528.50p +5.07%Antofagasta (ANTO) 1,094.00p +4.59%Rio Tinto (RIO) 3,046.50p +4.58%Aviva (AV.) 273.70p +4.51%FTSE 100 - FallersPennon Group (PNN) 763.50p -1.74%Vodafone Group (VOD) 179.00p -1.00%GlaxoSmithKline (GSK) 1,440.00p -0.41%Severn Trent (SVT) 1,642.00p -0.18%United Utilities Group (UU.) 674.50p 0.00%Experian (EXPN) 900.00p +0.11%Centrica (CNA) 316.80p +0.13%Tesco (TSCO) 312.75p +0.29%Morrison (Wm) Supermarkets (MRW) 266.90p +0.30%SSE (SSE) 1,382.00p +0.58%NR