London open: Stocks gain ahead of central bank announcements

- Investors await BoE and ECB decisions, FOMC minutes- Tate & Lyle jumps after Credit Suisse upgrades- Halfords appoints new CEO after strong Q2European stock markets have opened with moderate gains ahead of what is likely to be a busy day on the economic front, with rate decisions due out from the Bank of England (BoE) and European Central Bank (ECB) later today, as well as the minutes of the latest Federal Reserve meeting.The BoE's Monetary Policy Committee (MPC) is set to reveal whether it has made any alterations to its key interest rate and asset purchase programme (also known as quantitative easing, or QE) at noon.The smart money is on there being no change, with the interest rate staying at 0.5% and the asset purchase (quantitative easing, or QE) pot staying at £375bn. However, some are expecting an increase in QE and a 25 basis point rate cut in November.The ECB is also expected to remain in 'wait-and-see' mode when it reveals its policy decision after midday. Analysts believe that the ECB will wait for Spain to make the next move considering that it already announced its bond purchase plan for ailing countries that request aid. The key interest rate currently stands at 0.75% after it was cut by 25 basis points early in the year. The deposit rate is at 0%. Analyst Craig Erlam from Alpari said: "There's been a lack of volatility in the markets in recent weeks as investors look beyond central banks to the governments for reassurance on the next step in the debt crisis. The uncertainty surrounding Spain has left investors unsure on how to position themselves as we approach near end. Given a lack of details out of the eurozone, there is a hope that the ECB will give us some valuable insight into this."Meanwhile, the Federal Open Market Committee (FOMC) minutes are also on the agenda for later. Analyst Moyeen Islam from Barclays Research said this morning that the minutes should provide more "granularity regarding what the Fed may judge to be a 'sustainable improvement' in the labour market that would underpin any decision to end the current open-ended commitment to asset purchases.FTSE 100: Tate & Lyle gains after broker upgradeSweeteners and food products group Tate & Lyle was the high riser in early trading after Credit Suisse raised its recommendation for the stock from 'neutral' to 'outperform'. The broker said: "There is no easy way to value Tate & Lyle, but it does seem to us to be a better business for all the changes we have seen and that this is not reflected in the share price (which is down 8% year to date versus a staples sector up 18%)."Evraz fell after acquiring an indirect controlling interest in OJSC Raspadskaya, one of Russia's largest producers of coking coal and a supplier to the Russian steel firm.Pharmaceuticals behemoth GlaxoSmithKline gained after saying its joint venture company, Shionogi-ViiV Healthcare, has completed an initial clinical registration package for dolutegravir, its treatment for HIV patients.Supermarket peers Tesco and Sainsbury were among the stocks in the red following their results and trading update yesterday, respectively. Exane BNP Paribas reduced its target price for Tesco this morning from 325p to 300p and reiterated its 'underperform' rating on the shares. FTSE 250: Halfords surges after impressive Q2, new CEO appointmentCar and bike parts retailer Halfords jumped after appointing a new Chief Executive Officer following the abrupt departure of David Wild in the summer, as it revealed that full-year profits would be at the top end of guidance after a strong second quarter.The company expects pre-tax profit to be in the region of £40-42m in the first half on the back of its second quarter performance and an acceleration of operating cost investment. The consensus estimate currently stands at just £35.8m. Fashion chain Ted Baker was in demand after saying that the reaction to its autumn/winter collections has been positive as it unveiled a solid first-half trading performance. FTSE 100 - RisersTate & Lyle (TATE) 691.50p +2.52%Standard Chartered (STAN) 1,421.00p +1.21%Prudential (PRU) 833.00p +1.09%Carnival (CCL) 2,336.00p +0.99%InterContinental Hotels Group (IHG) 1,655.00p +0.98%Barclays (BARC) 222.30p +0.93%International Consolidated Airlines Group SA (CDI) (IAG) 165.20p +0.92%Royal Bank of Scotland Group (RBS) 260.40p +0.89%Diageo (DGE) 1,795.00p +0.84%ITV (ITV) 91.95p +0.82%FTSE 100 - FallersEvraz (EVR) 239.60p -3.11%BHP Billiton (BLT) 1,929.00p -0.72%Tesco (TSCO) 325.75p -0.67%G4S (GFS) 266.50p -0.56%BG Group (BG.) 1,302.00p -0.53%BP (BP.) 436.85p -0.50%CRH (CRH) 1,183.00p -0.50%Johnson Matthey (JMAT) 2,406.00p -0.46%Amec (AMEC) 1,145.00p -0.43%British Land Co (BLND) 521.00p -0.29%FTSE 250 - RisersHalfords Group (HFD) 302.00p +13.53%Ted Baker (TED) 945.00p +3.45%Victrex (VCT) 1,372.00p +3.08%Stobart Group Ltd. (STOB) 115.40p +2.58%Ocado Group (OCDO) 67.70p +2.27%Rentokil Initial (RTO) 84.85p +2.23%Computacenter (CCC) 385.00p +2.18%Paragon Group Of Companies (PAG) 212.30p +2.07%Lonmin (LMI) 548.00p +2.05%FirstGroup (FGP) 197.30p +2.02%FTSE 250 - FallersRank Group (RNK) 146.90p -2.39%Hansteen Holdings (HSTN) 76.30p -2.18%Carpetright (CPR) 630.00p -2.10%IP Group (IPO) 118.60p -1.58%JD Sports Fashion (JD.) 709.00p -1.53%Dechra Pharmaceuticals (DPH) 583.00p -1.10%Bovis Homes Group (BVS) 495.20p -1.06%Kenmare Resources (KMR) 39.75p -1.00%Petra Diamonds Ltd.(DI) (PDL) 115.20p -0.95%Utilico Emerging Markets Ltd (DI) (UEM) 160.12p -0.86%BC