London's top stocks are posting losses in early dealings on Thursday, tracking declines in the US and Asia after downbeat comments by the Federal Reserve about the US economy.The Fed said the US economy is improving but consumer spending has remained under pressure due to the tough jobs market and tight credit conditions. The London Stock Exchange is leading the fallers after it said the average daily value traded on its SETS electronic trading system declined by 43% in the five month ended August. 3i is also down. The private equity group has extended its revolving credit facilities to 31 October 2012 but cautioned that private equity and mergers and acquisition markets remain subdued.Pub group Mitchells & Butlers expects earnings for the current year to be slightly above current market estimates thanks to its improved sales performance. The group saw same outlet like-for-like sales growth of 2.6% in the 10 weeks to 19 September. In the 51 weeks, like-for-like sales growth was 1.6% and total retail sales were up by 3.4%.Defence group BAE Systems is to take full control of BVT Surface Fleet Limited, its joint venture with fellow defence firm VT Group. VT has exercised its option to sell its 45% holding in the company to BAE Systems for around £346m in cash.Losses soared at the discount sports retailer JJB Sports in the half year to July 26 during a tough period which saw the firm narrowly avoid going into administration. Pre-tax losses during the period widened to £42.9m from £13.9m as revenues slumped to £178.6m from £310.4m.Sterlite Industries, a subsidiary of Indian miner Vedanta Resources, said a chimney under construction at its BALCO site in Korba, India, has collapsed. Full scale relief and rescue operations are underway, with the involvement of the company and the government resources. Work activities in the immediate area have been temporarily suspended, but otherwise operations remain unaffected.Home maintenance specialist Homeserve said it has sold its emergency services division for up to £11m as it focuses on its higher margin, higher growth membership businesses. Property group Great Portland Estates has splashed out £45.8m on a retail and office building in the heart of London's financial district.Advertising firm M&C Saatchi saw revenues fall in the first half of 2009, but managed to stay profitable despite extremely difficult conditions for the sector. Pre-tax profits during the period fell to £5.4m from £8m over the same period the previous year as total revenues declined to £49.8m from £51.8m.Electronic components distributor Premier Farnell has acquired CadSoft Computer, a German-based computer aided design (CAD) developer, for up to €12m.FTSE 100 - RisersIntertek Group (ITRK) 1,260.00p +1.29%Autonomy Corporation (AU.) 1,579.00p +1.02%Alliance Trust (ATST) 313.00p +0.42%BT Group (BT.A) 135.40p +0.30%Cadbury (CBRY) 791.50p +0.25%Inmarsat (ISAT) 569.00p +0.18%Randgold Resources (RRS) 4,446.00p +0.16%FTSE 100 - FallersLondon Stock Exchange Group (LSE) 841.50p -4.32%3i Group (III) 277.00p -3.82%British Airways (BAY) 224.00p -2.57%Royal Bank of Scotland Group (RBS) 51.15p -2.48%Rexam (REX) 260.00p -2.44%International Power (IPR) 289.30p -2.06%Home Retail Group (HOME) 288.10p -2.01%