London midday: Profit-taking, Ukraine tensions hit UK stocks

- Ukraine accuses Russia of invasion- Sentiment dampened by ECB uncertainty- CSR jumps on takeover hopes- Xaar plummets on weak guidancetechMARK 2,838.91 -0.22%FTSE 100 6,799.21 -0.46%FTSE 250 15,898.75 -0.79%UK stocks retreated from an eight-week high on Thursday as renewed geopolitical tensions and uncertainty regarding European monetary policy prompted investors to take profits after the recent rally.By midday, the FTSE 100 was 0.5% lower at 6,799. The index closed at 6,830.66 on Wednesday, its highest finish since 4 July (6,866.05).Tensions in Ukraine have escalated after President Petro Poroshenko called for an emergency security meeting as pro-Russian rebels continued to take more ground in the south-east of the country. "An invasion of Russian forces has taken place," he said.Markets have risen in recent sessions as speculation grows that the European Central Bank (ECB) will introduce quantitative easing amid a continued worsening of economic data from the Eurozone. However, German Finance Minister Wolfgang Schäuble dampened sentiment after saying that comments from ECB president Mario Draghi about potential stimulus had been "over-interpreted".In other news, a measure of Eurozone economic confidence fell more than recently downgraded forecasts in August, according to the data for August published by the European Commission. Euro area business confidence fell to 100.6 from a downwardly revised 102.1 in July, missing forecasts for a reading of 101.5.CSR soars, Xaar plummetsWireless technology group CSR jumped on rumours that the firm is considering a sale. According to the Financial Times, the UK chipmaker has received takeover offers from a number of rival semiconductor manufacturers and could fetch a price of as much as $3bn, compared with Wednesday's closing price of $1.57bn.Xaar, the inkjet printing technology firm, saw shares sink after a weakening in third-quarter sales cast a further pall over already-disappointing interim results, with full-year expectations downgraded.Wm Morrison, which rose strongly on Wednesday after industry figures showed an improvement in sales at the UK supermarket, was extending gains as Deutsche Bank upgraded the stock from 'sell' to 'hold'. Tesco, however, was hit with a downgrade from 'buy' to 'hold'.Oil and gas stocks were mixed in morning trade. Tullow was on the rise after announcing several successful drilling results from a series of exploration, appraisal and testing activities conducted in blocks 10BB and 13T onshore Kenya.BP was trading lower after a fire broke out at its largest US refinery on Wednesday night. Nevertheless, the company said that operations at the Whiting refinery "were minimally impacted as a result of the incident and the refinery continues to produce products for customers".Afren was also in the red after saying it has suspended two more directors in relation to further "unauthorised payments". The firm last month suspended its chief executive and chief operating officer.Mining stocks were broadly lower as investors scaled back their appetite for risk, with Rio Tinto, Anglo American, Antofagasta and BHP Billiton among the worst performers on the blue-chip index.Precious metal producers Randgold Resources and Fresnillo, however, were bucking the trend as gold and silver prices rose on the back of safe-haven demand.FTSE 100 - RisersRandgold Resources Ltd. (RRS) 5,020.00p +1.60%Morrison (Wm) Supermarkets (MRW) 186.90p +1.36%Tullow Oil (TLW) 729.50p +1.18%Hammerson (HMSO) 613.50p +1.15%CRH (CRH) 1,414.00p +1.14%National Grid (NG.) 896.00p +0.84%Fresnillo (FRES) 935.50p +0.75%Severn Trent (SVT) 1,955.00p +0.51%Diageo (DGE) 1,771.50p +0.48%ARM Holdings (ARM) 964.50p +0.42%FTSE 100 - FallersRio Tinto (RIO) 3,217.50p -3.54%St James's Place (STJ) 709.50p -2.81%Anglo American (AAL) 1,526.50p -2.65%Sports Direct International (SPD) 718.50p -2.24%BHP Billiton (BLT) 1,902.50p -2.21%Antofagasta (ANTO) 790.50p -2.17%Intertek Group (ITRK) 2,775.00p -2.08%Hargreaves Lansdown (HL.) 1,151.00p -1.96%easyJet (EZJ) 1,344.00p -1.90%Kingfisher (KGF) 299.80p -1.70%FTSE 250 - RisersCSR (CSR) 769.50p +33.83%Playtech (PTEC) 710.50p +7.16%Imagination Technologies Group (IMG) 215.80p +5.89%IP Group (IPO) 212.90p +2.11%Hunting (HTG) 910.00p +1.73%DCC (DCC) 3,507.00p +1.45%Perform Group (PER) 213.00p +1.43%Diploma (DPLM) 709.50p +1.36%BH Macro Ltd. GBP Shares (BHMG) 1,964.00p +1.34%Ted Baker (TED) 1,927.00p +1.15%FTSE 250 - FallersXaar (XAR) 416.00p -25.71%Ocado Group (OCDO) 350.50p -13.16%Kazakhmys (KAZ) 290.10p -3.75%Hikma Pharmaceuticals (HIK) 1,683.00p -3.50%Ferrexpo (FXPO) 131.80p -3.37%AO World (AO.) 223.70p -3.16%Lonmin (LMI) 227.10p -2.99%AL Noor Hospitals Group (ANH) 1,134.00p -2.91%Afren (AFR) 107.30p -2.90%Pets at Home Group (PETS) 177.50p -2.79%BC