A fall in unemployment in Europe and some well-received corporate earnings pushed the FTSE 100 into positive territory on Wednesday morning, as traders showed optimism ahead of a policy announcement by the Federal Reserve later this evening.Some 24,000 fewer people were without a job in the Eurozone in June, the first decline in unemployment since April 2011. The jobless rate was unchanged at 12.1%. The rate for the wider 27-member European Union however fell from 11% to 10.9%.Meanwhile, German unemployment unexpectedly fell by 7,000 in July (forecast: no change), though the jobless rate was unchanged at 6.8%. "Encouraging unemployment data for the Eurozone has got things off to a positive start on Wednesday," said Market Analyst Craig Erlam from Alpari. "However, investors are clearly focused on one thing today, the FOMC statement, with European indices and US futures only trading marginally higher in response to the figures," he said.All eyes will be on the Federal Open Market Committee (FOMC) as its two-day meeting comes to a close this evening. While few actually think that the Fed will begin to scale back its quantitative easing programme this month - analysts are widely expecting the 'tapering' to start in September - traders will be on edge of their seats, looking out for hints of a timeframe for the impending withdrawal of stimulus.Second-quarter gross domestic product (GDP) figures will be due out in the States later on, along with the Chicago purchasing managers' index and the non-official ADP employment report (seen as a rough guide to Friday's official non-farm payrolls data).Erlam said: "There appears to be a slightly higher bias towards [tapering in] September at the moment, which is why the FOMC statement tonight is so important. This is the last meeting until September, so the statement should give a major clue about whether they are leaning towards tapering in September, or whether they'll hold off until December. "For me, I think it'll be December at the earliest. Especially if the GDP figure today is in line with, or below, expectations."Markets will also be looking ahead to the release of the Bank of England and European Central Bank policy decisions tomorrow afternoon.FTSE 100: Diageo, Antofagasta, Tullow and Centrica impress with H1 reportsDiageo, the beverages company behind the Guinness, Baileys and Smirnoff brands, achieved a solid 5.0% growth in full-year net sales, giving shares a lift this morning.South America-focused mining group Antofagasta gained despite seeing copper output fall from the first to the second quarter, as it said it was still on track to hit its full-year target of 700,000 tonnes, more or less in line with last year.Oil explorer Tullow was higher after reporting a 15% jump in first-half revenue to $1.3bn on the back of an increase in production. Sector peer BP meanwhile was rebounding after investors yesterday gave a cool reaction to its second-quarter results.Centrica, the energy company which owns British Gas, also rose after reporting a "robust" financial performance in the six months to June 30th, with revenue up 14% at £13.7bn after customers used more gas to stay warm during an unusually cold winter.Meanwhile, engineer GKN was performing well, extending gains after its well-received first-half report yesterday. The stock was given a lift this morning by Investec which upgraded its rating from 'add' to 'buy'.In contrast, banking group Barclays was extending losses made the day before after it revealed plans for a £5.8bn rights issue and reported a drop in profits in the first half. Sector peers Lloyds and RBS were also under pressure ahead their results over the next few days.Utilities firm SSE however was the standout faller after going ex-dividend.FTSE 100 - RisersDiageo (DGE) 2,043.50p +2.71%Antofagasta (ANTO) 894.50p +2.23%National Grid (NG.) 786.00p +2.14%GKN (GKN) 355.80p +2.09%Melrose Industries (MRO) 282.90p +2.09%SABMiller (SAB) 3,204.00p +2.05%Croda International (CRDA) 2,545.00p +2.00%Tullow Oil (TLW) 1,046.00p +1.85%HSBC Holdings (HSBA) 747.40p +1.52%Centrica (CNA) 391.20p +1.40%FTSE 100 - FallersSSE (SSE) 1,575.00p -3.85%easyJet (EZJ) 1,394.00p -1.20%Barclays (BARC) 288.20p -1.06%International Consolidated Airlines Group SA (CDI) (IAG) 289.40p -0.65%Smith & Nephew (SN.) 778.00p -0.64%RSA Insurance Group (RSA) 125.50p -0.63%Tesco (TSCO) 364.70p -0.53%Aviva (AV.) 372.30p -0.48%Weir Group (WEIR) 2,154.00p -0.46%Randgold Resources Ltd. (RRS) 4,801.00p -0.46%FTSE 250 - RisersRightmove (RMV) 2,455.00p +6.28%Rank Group (RNK) 159.00p +4.61%F&C Asset Management (FCAM) 98.40p +4.13%St James's Place (STJ) 617.50p +4.04%Essentra (ESNT) 778.50p +3.94%Bumi (BUMI) 221.00p +3.66%Brewin Dolphin Holdings (BRW) 252.20p +3.23%SEGRO (SGRO) 309.10p +3.03%Renishaw (RSW) 1,573.00p +2.74%African Barrick Gold (ABG) 114.40p +2.69%FTSE 250 - FallersMoneysupermarket.com Group (MONY) 179.00p -15.65%Evraz (EVR) 95.30p -4.17%Dignity (DTY) 1,495.00p -2.73%Barratt Developments (BDEV) 327.50p -2.24%KCOM Group (KCOM) 82.05p -1.91%Investec (INVP) 437.90p -1.90%Imagination Technologies Group (IMG) 235.80p -1.87%COLT Group SA (COLT) 101.30p -1.84%International Personal Finance (IPF) 636.00p -1.70%888 Holdings (888) 163.00p -1.69%BC