London open: Stocks fall on growth concerns again

- Growth concerns take down stocks again- Alcoa trims demand forecast- Banks could need to shrink assets, says IMFThe FTSE 100 was heading for its third consecutive day in the red, starting Wednesday's session on the back foot with global growth concerns continuing to weigh on sentiment.Trader Simon Furlong said this morning that today looks like "another down day for the markets unless some positive news flow is received".Stocks slipped yesterday after the International Monetary Fund (IMF) cut its global growth forecasts for this year and the next. On Monday, the World Bank lowered its growth estimates for East Asia, warning of a deceleration in the Chinese economy.Meanwhile, US aluminium giant Alcoa kicked off third-quarter earnings season last night after the closing bell on Wall Street. While the firm beat earnings and sales forecasts, the company cut its full-year aluminium demand growth forecast from 7% to 6%, saying that a slowdown in China "slightly impacts the second-half outlook".Risks to global financial stability have increased and financial markets have been volatile as European policymakers grapple with the ongoing crisis, the IMF said in its latest assessment of the global financial sector. The Fund notes that failing to deal with the current issues could end up forcing Eurozone banks into an asset shrinkage of anywhere from $2.8tn to $4.5tn by the end of next year. Ex-div stocks take a hitSmith & Nephew, Kingfisher and Wolseley were among the falls early on after going ex-dividend. From today, investors will not be able to get hold of their latest dividend payments. Banking groups were in demand in the opening hour with Lloyds, RBS and Barclays making gains. RBS has agreed to sell two building in Frankfurt and Berlin to Axa Investment Managers, the largest German commercial real estate transaction this year, according to reports.Outsourcing group Capita was a heavy faller after both RBC Capital Markets and Panmure Gordon downgraded their ratings for the stock. Panmure said that the Capita's premium rating "is at odds with concerns over the quality of future earnings, above average financial leverage and on-going reliance on M&A."Drinks giant SABMiller edged higher after expanding its African beer brand, Chibuku, into ten countries across the continent.On the FTSE 250, N Brown, the internet and catalogue home shopping firm, was a heavy faller after Panmure Gordon downgraded its recommendation to 'hold' ahead of the group's interim results next week. "We move to a 'hold' rating from 'buy', following sector outperformance and consequent multiple expansion towards our target multiple on the back of the July trading statement," the broker said.FTSE 100 - RisersLloyds Banking Group (LLOY) 38.33p +3.57%Royal Bank of Scotland Group (RBS) 263.10p +2.25%Anglo American (AAL) 1,840.50p +1.49%Evraz (EVR) 250.40p +1.21%Barclays (BARC) 224.00p +1.11%Kazakhmys (KAZ) 736.00p +0.96%InterContinental Hotels Group (IHG) 1,657.00p +0.91%BT Group (BT.A) 223.50p +0.81%Rio Tinto (RIO) 3,053.00p +0.76%Eurasian Natural Resources Corp. (ENRC) 328.20p +0.71%FTSE 100 - FallersSmith & Nephew (SN.) 654.00p -2.75%Aggreko (AGK) 2,198.00p -1.88%WPP (WPP) 857.50p -1.61%Wolseley (WOS) 2,644.00p -1.60%Capita (CPI) 730.00p -1.35%Tesco (TSCO) 310.65p -1.21%Rexam (REX) 448.10p -1.21%Kingfisher (KGF) 268.00p -1.18%Marks & Spencer Group (MKS) 377.00p -1.13%Compass Group (CPG) 684.00p -1.08%FTSE 250 - RisersMan Group (EMG) 95.05p +5.67%Ruspetro (RPO) 104.40p +2.15%Bumi (BUMI) 169.50p +2.05%Fidessa Group (FDSA) 1,377.00p +2.00%Lonmin (LMI) 516.00p +1.98%Petropavlovsk (POG) 442.40p +1.70%Stobart Group Ltd. (STOB) 115.00p +1.68%Lancashire Holdings (LRE) 843.00p +1.63%Bank of Georgia Holdings (BGEO) 1,173.00p +1.21%Ted Baker (TED) 920.00p +1.10%FTSE 250 - FallersCOLT Group SA (COLT) 116.70p -2.59%Brown (N.) Group (BWNG) 271.80p -2.51%Senior (SNR) 196.10p -2.44%JD Sports Fashion (JD.) 757.00p -2.13%Micro Focus International (MCRO) 572.00p -1.89%Heritage Oil (HOIL) 187.00p -1.84%Balfour Beatty (BBY) 301.60p -1.76%Cranswick (CWK) 720.00p -1.71%Sports Direct International (SPD) 392.20p -1.58%Oxford Instruments (OXIG) 1,351.00p -1.53%BC