London close: Buoyant RBS, Barclays and Lloyds boost FTSE 100

Stocks rediscovered their earlier strength, but only after tumbling below the 5,000 point mark on another volatile day for the leading share index.Banks were prominent among the risers, with Barclays, Lloyds and RBS posting decent gains, after talk of a 50 basis point cut in European Central Bank interest rates helped to lift sentiment.Car parts and bicycle retailer Halfords pedalled higher on an upgrade to "buy" from "hold" at Oriel Securities, despite predicting a poor trading update.Oil group Exillon tumbled but it was a mystery mover with no apparent reason, save the lower oil price, for its tumble. Private equity investor 3i, which warned that falling stock markets will lead to an inevitable fall in the value of its portfolio at the half-year stage but said net debt has decreased from its year-end (March) level of £522m to £343 million at 31 August, finished flat after fluctuating between the red and the blue.Euromoney Institutional Investor finished higher. The business-to-business publisher and events organiser, has seen a slow-down in the rate of growth of advertising and event sponsorship sales in the last couple of months but bookings for events and courses have held up well, while subscriptions revenues, which account for approximately half the group's total revenues, have continued to grow at similar rates to the third quarter. Total revenues for the year to September 30, 2011 are expected to show a headline increase of around 10% on 2010. The stock benefited from an upgrade to "buy" from "add" at Numis.British Gas owner Centrica's North American subsidiary, Direct Energy, has agreed to acquire the Texas-based energy retailer First Choice Power for $270m (£175m) in cash, plus additional working capital.Among smaller companies, mail order gardening, gift and audiobook retailer Flying Brands came crashing back to earth after saying it is in negotiations to sell property assets to avoid breaching its banking covenants following a sharp deterioration in trading.Internet domain name management and web hosting firm Group NBT jumps after saying is set to go private after the group's directors recommended a takeover bid from private equity outfit HgCapital Funds. HgCapital is setting up a company, Newton Bidco, to offer 550p cash per NBT share, a premium of just over a pound to the closing price of Group NBT on the day before the bid announcement. The terms value Group NBT at around £153m.FTSE 100 - RisersBarclays (BARC) 146.00p +5.15%Lloyds Banking Group (LLOY) 34.15p +5.03%Man Group (EMG) 231.40p +4.71%Royal Bank of Scotland Group (RBS) 22.83p +3.54%Imperial Tobacco Group (IMT) 2,086.00p +3.42%Admiral Group (ADM) 1,271.00p +3.33%Standard Life (SL.) 194.70p +3.29%Inmarsat (ISAT) 477.80p +3.17%Tesco (TSCO) 365.20p +2.51%ITV (ITV) 57.75p +2.48%FTSE 100 - FallersWeir Group (WEIR) 1,546.00p -6.25%Randgold Resources Ltd. (RRS) 6,350.00p -4.73%Fresnillo (FRES) 1,636.00p -4.27%Kazakhmys (KAZ) 814.00p -3.84%Aggreko (AGK) 1,681.00p -2.83%Xstrata (XTA) 826.00p -2.77%Eurasian Natural Resources Corp. (ENRC) 554.00p -2.72%Rexam (REX) 300.90p -2.56%GKN (GKN) 172.70p -2.54%IMI (IMI) 725.50p -2.49%FTSE 250 - RisersCOLT Group SA (COLT) 104.50p +6.96%Halfords Group (HFD) 313.10p +6.32%Cranswick (CWK) 615.50p +4.59%Sports Direct International (SPD) 227.40p +3.74%easyJet (EZJ) 352.00p +3.53%Betfair Group (BET) 745.00p +3.04%London Stock Exchange Group (LSE) 837.00p +2.89%Home Retail Group (HOME) 116.90p +2.63%Paragon Group Of Companies (PAG) 145.60p +2.54%Cable & Wireless Communications (CWC) 39.54p +2.44%FTSE 250 - FallersExillon Energy (EXI) 206.00p -20.46%Thomas Cook Group (TCG) 36.09p -7.01%JPMorgan Russian Securities (JRS) 443.90p -6.15%Salamander Energy (SMDR) 182.30p -5.59%Centamin Egypt Ltd. (CEY) 99.90p -5.58%Lamprell (LAM) 249.20p -5.32%Hochschild Mining (HOC) 464.40p -5.09%Ferrexpo (FXPO) 296.50p -5.03%Spectris (SXS) 1,200.00p -4.99%Yule Catto & Co (YULC) 148.00p -4.88%