London midday: Stocks set for weekly gain as miners rise

- Miners recover after recent slump- Obama imposes more sanctions on Russia- Markets await speeches from Fed officials- Burberry, RBS, Hikma hit by broker downgradestechMARK 2,807.91 +0.27%FTSE 100 6,564.71 +0.34%FTSE 250 16,228.56 +0.07%UK equities were trading higher on Friday with the FTSE 100 set to finish the week in positive territory, helped by a strong performance by mining stocks which recovered after their recent slump."Ongoing geopolitical tensions in the Ukraine together with Fed chair Yellen's remarks regarding monetary tightening keep us anxious in general but as we head to the end of the week, traders are demonstrating a level of comfort," said Market Strategist Ishaq Siddiqi from ETX Capital.The FTSE 100 was 0.3% higher at 6,565 by midday, trading 0.5% above its closing price last Friday.Despite the gains, developments in Ukraine were being closely watched today as Vladimir Putin signed a bill to incorporate Crimea into Russia. The move comes after European Union (EU) and US leaders imposed more sanctions on Russian officials yesterday.President Barack Obama announced yesterday that he would extend financial sanctions to more of Vladimir Putin's 'inner circle', including wealthy supporters and a bank close to the Kremlin. The new sanctions prompted ratings agency Standard & Poor's to revise its outlook on Russian debt from 'stable' to 'negative' due to "rising geopolitical and economic risks".Markets were also awaiting speeches from four members of the US Federal Reserve following Janet Yellen's revelation on Wednesday that interest rates may rise sooner than expected. Alongside the Fed's decision this week to taper asset purchases by $10bn a month again, Yellen signalled that the first rate hike could come "around six months" after quantitative easing ends.Fed officials James Bullard, Richard Fisher, Narayana Kocherlakota and Jeremy Stein are all due to talk later on this evening.Miners rise; Burberry, RBS and Hikma hit by downgradesMining stocks were performing well this morning as bargain hunters stepped in following recent weakness in the sector. At Thursday's close, the FTSE 350 mining sector had lost over 11% over the last four weeks. Diversified resources giant Anglo American and precious metals producer Fresnillo were among the best performers today, along with Rio Tinto and Glencore Xstrata. Luxury brand Burberry was a heavy faller this morning after Bank of America Merrill Lynch lowered its rating on the stock from 'buy' to 'neutral'.Banking group RBS was also hit with a downgrade by Barclays Capital from 'overweight' to 'equal weight'. Pharmaceuticals firm Hikma was also trading in the red this morning after Jefferies cut the stock from 'buy' to 'hold'.In contrast, UBS has upgraded its rating on aerospace, defence and energy engineer Meggitt from 'neutral' to 'buy', giving the stock a lift. The bank said that the 11% fall in the shares since mid-Ferbuary was "overdone" and the "stock offers good value at these levels".Crest Nicholson dropped after Bloomberg reported that the housebuilder's largest publicly disclosed shareholder, Deutsche Bank, is disposing of as many as 16.5m shares. The German bank is thought to have 10% stake in the company.FTSE 100 - RisersFresnillo (FRES) 886.50p +2.31%InterContinental Hotels Group (IHG) 1,903.00p +1.98%Anglo American (AAL) 1,439.00p +1.95%Rio Tinto (RIO) 3,218.00p +1.93%Imperial Tobacco Group (IMT) 2,461.00p +1.78%Intertek Group (ITRK) 2,990.00p +1.74%Tate & Lyle (TATE) 653.50p +1.55%Glencore Xstrata (GLEN) 305.50p +1.38%Standard Chartered (STAN) 1,200.50p +1.35%HSBC Holdings (HSBA) 601.90p +1.30%FTSE 100 - FallersRoyal Bank of Scotland Group (RBS) 298.60p -2.19%Burberry Group (BRBY) 1,389.00p -2.18%Legal & General Group (LGEN) 208.90p -1.97%Aberdeen Asset Management (ADN) 366.70p -1.95%Hargreaves Lansdown (HL.) 1,431.00p -1.65%Barclays (BARC) 234.75p -1.63%Travis Perkins (TPK) 1,827.00p -1.35%Marks & Spencer Group (MKS) 465.90p -1.12%Aviva (AV.) 488.70p -1.01%Schroders (SDR) 2,648.00p -0.97%FTSE 250 - RisersXaar (XAR) 859.00p +4.12%Investec (INVP) 465.50p +4.00%Partnership Assurance Group (PA.) 128.00p +3.23%Polymetal International (POLY) 631.50p +2.85%Interserve (IRV) 684.00p +2.78%De La Rue (DLAR) 802.00p +2.69%Vedanta Resources (VED) 853.50p +2.65%Homeserve (HSV) 312.80p +2.59%RPS Group (RPS) 332.00p +2.47%Essar Energy (ESSR) 67.50p +2.27%FTSE 250 - FallersCrest Nicholson Holdings (CRST) 382.90p -4.28%Ocado Group (OCDO) 457.60p -3.91%Hikma Pharmaceuticals (HIK) 1,614.00p -3.41%Cairn Energy (CNE) 160.50p -2.13%Kenmare Resources (KMR) 14.38p -2.11%ITE Group (ITE) 215.60p -1.87%Ophir Energy (OPHR) 255.30p -1.81%Mitie Group (MTO) 317.80p -1.76%Atkins (WS) (ATK) 1,368.00p -1.72%Brown (N.) Group (BWNG) 559.50p -1.67%BC