The Footsie held on to gains by the close, helped by some helpful economic data at home and abroad. It seems as if the 'Santa rally' that many had put on their Christmas lists has finally started to bear fruit with London's blue chip index finished at the highest closing level since last Tuesday.BANKS PROVIDE A LIFTLloyds led the way on the FTSE 100, followed closely by RBS and Old Mutual as stocks rallied on news that the UK gross domestic product (GDP) grew by 0.6% in the third quarter in volume terms versus the previous three months, according to the latest data released this morning by the Office for National Statistics (ONS). Market consensus was for a reading of 0.5%. Meanwhile, the US Department of Labor has revealed that initial unemployment claims for the week ending December 18 fell by 4,000 to 364,000, compared with market consensus looking for a reading of 380,000 claims. The Thomson Reuters/University of Michigan consumer sentiment index also boosted the mood, increasing to 69.9 this month from 64.1 at the end of November. This surpassed consensus expectations of 68 and a preliminary reading of 67.7.The big company story of the day was International Airlines Group (IAG), which managed to land airline British Midland (bmi) after protracted negotiations with current owner, Deutsche Lufthansa. IAG, the company formed by the merger of British Airways and Iberia, is to pay £172.5m in cash for bmi from its own funds. Shares rose over 3% after the firm said that the acquisition would expand its presence at Heathrow airport and add €100m to its €1.5bn operating profit target for 2015.FTSE 250 RETAILERS LEAD THE RISE Retailers led the way on the FTSE 250, with Ocado, Carpetright, Home Retail and SuperGroup registering decent gains, after Credit Suisse said it was "cautiously optimistic" on the UK retail sector. "Demand conditions for 2012 remain uncertain, although we are cautiously optimistic on the UK environment versus the rest of Europe," the Swiss broker said. "Annualising against the VAT increase, food price inflation as well as easing raw material costs (cotton) should provide some underpinning to UK forecast expectations."However, the broker did warn that "Operational gearing is an issue in the short term although investors are in our view aware of demand related issues and consumer pressures into 2012." Stagecoach fell after JP Morgan downgraded the stock from overweight to underweight.Hansteen rose after the investor in UK and Continental European property bought up the entire property assets of The Spencer Group of Companies, a commercial property specialist. Perform Group, the digital media firm specialising in sports content, finished higher after signing a four-year deal with the Women's Tennis Association (WTA) to manage and oversee the development of all media rights for the WTA from the start of 2013 to the end of 2016, outside of the USA and Canada.SMALL CAP MOVERSDVD and film distributor Metrodome saw shares plunge over 26 after warning that operating profit for the year to 31 December 2011 is expected to be materially below current market expectations. "Despite the group's trading divisions Metrodome Distribution and Hollywood Classics trading in line with expectations, Target Entertainment, the group's TV distribution business, has experienced tougher than expected trading conditions in the final quarter of the year," the group explained in a company statement. AIM-quoted diagnostic tests and testing equipment supplier Avacta tumbled 20% after conditionally placing 1.03m shares at 0.5p, and announcing the £1.48m acquisition of diagnostics firm Aptuscan. FTSE 100 - RisersOld Mutual (OML) 135.60p +4.15%Royal Bank of Scotland Group (RBS) 20.61p +3.99%Evraz (EVR) 390.00p +3.92%Lloyds Banking Group (LLOY) 25.85p +3.67%Kazakhmys (KAZ) 917.00p +3.56%ITV (ITV) 64.45p +3.45%International Consolidated Airlines Group SA (IAG) 149.90p +3.31%Polymetal International (POLY) 1,109.00p +2.88%Aviva (AV.) 299.60p +2.67%Schroders (Non-Voting) (SDRC) 1,056.00p +2.62%FTSE 100 - FallersVedanta Resources (VED) 1,017.00p -2.40%Randgold Resources Ltd. (RRS) 6,585.00p -1.72%Carnival (CCL) 2,107.00p -1.13%Compass Group (CPG) 588.00p -0.59%Man Group (EMG) 125.40p -0.40%Reed Elsevier (REL) 503.50p -0.30%Reckitt Benckiser Group (RB.) 3,125.00p -0.26%Whitbread (WTB) 1,524.00p -0.07%United Utilities Group (UU.) 589.00p 0.00%Severn Trent (SVT) 1,454.00p 0.00%FTSE 250 - RisersOcado Group (OCDO) 59.00p +11.64%Carpetright (CPR) 508.00p +10.12%Allied Gold Mining (ALD) 144.50p +5.40%Perform Group (PER) 210.00p +5.00%Supergroup (SGP) 502.00p +4.58%Home Retail Group (HOME) 83.50p +4.51%Hansteen Holdings (HSTN) 72.40p +3.65%Afren (AFR) 85.95p +3.55%Spirent Communications (SPT) 113.80p +3.45%Barratt Developments (BDEV) 90.05p +3.15%FTSE 250 - FallersStagecoach Group (SGC) 260.90p -3.44%DS Smith (SMDS) 187.30p -2.65%JD Sports Fashion (JD.) 602.50p -2.59%International Personal Finance (IPF) 167.70p -2.50%Domino Printing Sciences (DNO) 503.00p -2.33%Brewin Dolphin Holdings (BRW) 135.80p -2.23%Phoenix Group Holdings (DI) (PHNX) 506.00p -2.22%Regus (RGU) 80.00p -2.08%Rightmove (RMV) 1,214.00p -2.02%New World Resources A Shares (NWR) 433.00p -1.84%