UK stocks opened flat on Wednesday morning as investors digested a barrage of blue-chip earnings and awaited a Federal Reserve policy decision in the US.The FTSE 100 was trading just 0.03% lower at 7,028.48 early on.The index had retreated on Tuesday to 7,030.53 after setting a new all-time closing high of 7,103.98 on Monday."Even though we saw European markets fall sharply yesterday, stock markets have remained broadly within the ranges they've been in for the last few weeks, and that's broadly been true of US markets as well, even if we have seen marginal new all-time highs on the S&P500 and the FTSE100 this week," said analyst Michael Hewson from CMC Markets.The focus of Wednesday's session will likely be on the States with the Federal Open Market Committee (FOMC) due to announce its vote on monetary policy at 19:00.US gross domestic product (GDP) figures are also due out at 13:30 and are expected to reveal that annualised growth slowed to just 1% in the first quarter from 2.2% in the fourth quarter.Analysts at Deutsche Bank said the FOMC statement "will be interesting as to how much they put recent weakness down to transitory factors".Earnings on tapBanking group Barclays declined after first-quarter results showed statutory group profits decreased 26% to £1.4bn. However, adjusted profits were up 9% over last year, while the lender's capital buffers improved.High street retailer Next was in fashion after first-quarter sales rose 3.2%, ahead of the 0% to +3% growth guidance given in March. More than half of the rise came from the opening of new space, with warmer weather and an earlier brochure also helping.Antofagasta was weaker as the copper miner scaled back its production guidance after first-quarter output was affected by numerous water issues at its Los Pelambres and Centinela projects. Mining stocks on the whole were out of favour, with BHP Billiton, Rio Tinto and Anglo American all registering losses.British American Tobacco fell after disappointing with a first-quarter update, which revealed that constant-currency revenues were down 5.8% amid a "challenging trading environment".London Stock Exchange rose after saying it made a good start to the year with group revenues up 86% at £581m.Industrial engineer Weir Group edged higher despite saying it was "taking further action to support profitability" with further cost cuts in its oil and gas division after a challenging first quarter.Vodafone was performing well after the telecoms stock was upgraded by Berenberg to 'buy'. The broker hiked its target price for the shares from 214p to 270p.Sainsbury fell on the news that its chief executive Mike Coupe was handed a two-year jail sentence in Egypt.Market MoverstechMARK 3,231.28 +0.23%FTSE 100 7,028.48 -0.03%FTSE 250 17,628.56 -0.17%FTSE 100 - RisersNext (NXT) 7,390.00p +3.14%Coca-Cola HBC AG (CDI) (CCH) 1,422.00p +2.45%Marks & Spencer Group (MKS) 563.50p +1.53%Vodafone Group (VOD) 232.70p +1.28%Royal Mail (RMG) 443.10p +1.26%Shire Plc (SHP) 5,460.00p +1.20%United Utilities Group (UU.) 998.00p +1.17%Hargreaves Lansdown (HL.) 1,238.00p +1.14%St James's Place (STJ) 885.50p +1.14%Old Mutual (OML) 234.60p +1.12%FTSE 100 - FallersAntofagasta (ANTO) 782.00p -2.49%British American Tobacco (BATS) 3,601.00p -1.87%BHP Billiton (BLT) 1,563.00p -1.67%Rio Tinto (RIO) 2,931.00p -1.63%Imperial Tobacco Group (IMT) 3,226.00p -1.07%BP (BP.) 471.45p -0.98%Morrison (Wm) Supermarkets (MRW) 190.20p -0.89%Barclays (BARC) 259.30p -0.80%Sainsbury (J) (SBRY) 264.10p -0.75%3i Group (III) 508.50p -0.68%FTSE 250 - RisersBrown (N.) Group (BWNG) 336.20p +4.47%Home Retail Group (HOME) 171.50p +2.51%NMC Health (NMC) 680.50p +2.48%Man Group (EMG) 207.80p +1.86%AO World (AO.) 189.40p +1.83%Greggs (GRG) 1,094.00p +1.67%Ocado Group (OCDO) 350.70p +1.33%Halfords Group (HFD) 459.80p +1.03%Moneysupermarket.com Group (MONY) 277.40p +1.02%FirstGroup (FGP) 101.10p +1.00%FTSE 250 - FallersOphir Energy (OPHR) 163.80p -4.15%COLT Group SA (COLT) 143.00p -3.31%Lonmin (LMI) 143.90p -2.70%Countrywide (CWD) 511.50p -2.57%IP Group (IPO) 200.00p -2.53%BlackRock World Mining Trust (BRWM) 312.50p -2.16%Jimmy Choo (CHOO) 169.50p -1.97%Indivior (INDV) 195.20p -1.96%Computacenter (CCC) 684.50p -1.93%Bank of Georgia Holdings (BGEO) 1,791.00p -1.76%