London open: UK stocks bounce off three-week low but gains limited

UK stocks edged higher on Friday but choppy trading continued with investors concerned about the potential impact from a 'yes' vote on Scottish independence next week.Supermarket stocks were among the best performers as Morrisons extended gains made the previous session, while banks advanced, though gains were limited early on. Meanwhile, the share price of Aveva sank by a fifth after a gloomy first-half trading update.London's FTSE 100, which has traded within a tight range for the whole week, was just 0.1% higher at 6,807 in early deals after closing below the 6,800 mark on Thursday for the first time since 22 August.Despite a YouGov opinion poll on Thursday showing that the 'no' campaign was back in the lead ahead of the 18 September Scottish referendum, the International Monetary Fund spread fears about the risks of a potential 'yes' vote, saying that it could lead to turmoil in financial markets.The IMF deputy spokesman, William Murray, said at a press briefing that a vote to separate Scotland from the rest of the UK "would raise a number of important and complicated issues that would have to be negotiated".He said that a 'yes' vote would create "uncertainty" and "could lead to negative market reactions in the short term".Aveva plummets, Morrisons risesAveva shares were down around 20% in morning trade after the software company said revenues in the first half would be as much as 23% lower than last year due to negative currency movements and the timing of rental renewals. The group said it was reviewing its headcount growth plans and spending.Heading the other way was supermarket group Morrisons as investors continued to digest Thursday's interim results. The company announced a 51% drop in underlying profits but kept to its promise to raise its dividend by 5% and maintained its guidance for an increase in the full-year payout. Rival grocer Sainsburys was also on the up early on.Banking stocks were also providing a lift to markets with RBS, Lloyds and Barclays making gains. Scotland-based RBS and Lloyds have both said that they would have to re-domicile in England in the event of a 'yes' vote for Scottish independence.Miners were putting in a mixed performance with Rio Tinto and BHP Billiton in positive territory and Anglo American and Glencore in the red.Fresnillo inched higher after proposing to spend $450m on buying out its joint venture partner to take full ownership of certain assets in the Herradura Corridor, one of Mexico's most prospective gold belts.Market MoverstechMARK 2,840.05 -0.13%FTSE 100 6,807.39 +0.11%FTSE 250 15,654.23 +0.21%FTSE 100 - RisersMorrison (Wm) Supermarkets (MRW) 180.10p +1.29%Tullow Oil (TLW) 706.50p +1.29%Sainsbury (J) (SBRY) 288.10p +0.98%Barratt Developments (BDEV) 382.80p +0.92%Carnival (CCL) 2,396.00p +0.88%Royal Bank of Scotland Group (RBS) 349.00p +0.87%Reckitt Benckiser Group (RB.) 5,410.00p +0.84%Schroders (SDR) 2,446.00p +0.78%Admiral Group (ADM) 1,243.00p +0.65%ARM Holdings (ARM) 954.50p +0.63%FTSE 100 - FallersAggreko (AGK) 1,635.00p -1.03%Whitbread (WTB) 4,288.00p -0.92%Associated British Foods (ABF) 2,655.00p -0.82%Anglo American (AAL) 1,484.00p -0.74%Aviva (AV.) 527.50p -0.66%Kingfisher (KGF) 318.20p -0.56%Petrofac Ltd. (PFC) 1,067.00p -0.56%Intu Properties (INTU) 337.90p -0.56%Bunzl (BNZL) 1,609.00p -0.49%British Sky Broadcasting Group (BSY) 864.00p -0.46%FTSE 250 - RisersEvraz (EVR) 119.60p +3.28%Domino Printing Sciences (DNO) 620.00p +2.90%Alent (ALNT) 352.00p +2.33%Just Retirement Group (JRG) 139.00p +1.91%Tullett Prebon (TLPR) 280.70p +1.89%Bwin.party Digital Entertainment (BPTY) 97.20p +1.89%Centamin (DI) (CEY) 62.25p +1.88%Serco Group (SRP) 319.50p +1.75%Ladbrokes (LAD) 129.70p +1.57%Brit (BRIT) 244.70p +1.49%FTSE 250 - FallersAveva Group (AVV) 1,731.00p -20.16%Ocado Group (OCDO) 302.60p -3.23%Kazakhmys (KAZ) 279.10p -3.02%Hochschild Mining (HOC) 157.30p -1.75%African Barrick Gold (ABG) 226.80p -1.48%Kier Group (KIE) 1,663.00p -1.01%Dechra Pharmaceuticals (DPH) 757.50p -0.98%Poundland Group (PLND) 311.40p -0.89%Drax Group (DRX) 651.00p -0.84%Spirent Communications (SPT) 104.20p -0.67%