London midday: FTSE 100 below 5,000 points

This morning's rally is a distant memory now with stocks tumbling below the 5,000 point mark as nerves set in again.Miners are prominent in the firing line as metals prices slide, with Xstrata and Kazakhmys sharply lower. Gold miner Centamin Egypt is also suffering big losses. Copper fell by 7%.Tesco, which has been angering its fellow supermarkets with a new "Big Price Drop" is bucking the trend though.Private equity investor 3i, which warned that falling stock markets will lead to an inevitable fall in the value of its portfolio at the half-year stage but said net debt has decreased from its year-end (March) level of £522m to £343 million at 31 August, has given up gains.Euromoney Institutional Investor falls back. The business-to-business publisher and events organiser, has seen a slow-down in the rate of growth of advertising and event sponsorship sales in the last couple of months but bookings for events and courses have held up well, while subscriptions revenues, which account for approximately half the group's total revenues, have continued to grow at similar rates to the third quarter. Total revenues for the year to September 30, 2011 are expected to show a headline increase of around 10% on 2010.British Gas owner Centrica's North American subsidiary, Direct Energy, has agreed to acquire the Texas-based energy retailer First Choice Power for $270m (£175m) in cash, plus additional working capital.Among smaller companies, mail order gardening, gift and audiobook retailer Flying Brands is in negotiations to sell property assets to avoid breaching its banking covenants following a sharp deterioration in trading.Internet domain name management and web hosting firm Group NBT jumps after saying is set to go private after the group's directors recommended a takeover bid from private equity outfit HgCapital Funds. HgCapital is setting up a company, Newton Bidco, to offer 550p cash per NBT share, a premium of just over a pound to the closing price of Group NBT on the day before the bid announcement. The terms value Group NBT at around £153m. FTSE 100 - RisersVodafone Group (VOD) 161.25p +1.32%Tesco (TSCO) 359.70p +0.97%Unilever (ULVR) 1,953.00p +0.83%Centrica (CNA) 284.40p +0.64%Admiral Group (ADM) 1,237.00p +0.57%Imperial Tobacco Group (IMT) 2,027.00p +0.50%SABMiller (SAB) 2,055.00p +0.39%Serco Group (SRP) 491.10p +0.04%Autonomy Corporation (AU.) 2,517.00p -0.04%Associated British Foods (ABF) 1,078.00p -0.09%FTSE 100 - FallersWeir Group (WEIR) 1,531.00p -7.16%Xstrata (XTA) 791.40p -6.84%Kazakhmys (KAZ) 789.50p -6.73%Vedanta Resources (VED) 1,045.00p -6.45%Eurasian Natural Resources Corp. (ENRC) 536.50p -5.79%Antofagasta (ANTO) 924.50p -4.94%Petrofac Ltd. (PFC) 1,198.00p -4.69%Rio Tinto (RIO) 2,883.50p -4.61%IMI (IMI) 710.50p -4.50%ARM Holdings (ARM) 549.50p -4.43%FTSE 250 - RisersHalfords Group (HFD) 308.90p +4.89%Interserve (IRV) 302.20p +4.03%Daejan Holdings (DJAN) 2,385.00p +2.85%Cranswick (CWK) 602.00p +2.29%Redrow (RDW) 109.20p +2.06%COLT Group SA (COLT) 99.40p +1.74%JD Sports Fashion (JD.) 846.50p +1.68%Paragon Group Of Companies (PAG) 144.00p +1.41%F&C Asset Management (FCAM) 62.80p +1.37%Carpetright (CPR) 483.80p +0.79%FTSE 250 - FallersLamprell (LAM) 232.30p -11.74%Centamin Egypt Ltd. (CEY) 94.60p -10.59%Exillon Energy (EXI) 233.40p -9.88%New World Resources A Shares (NWR) 444.20p -8.88%JPMorgan Russian Securities (JRS) 433.00p -8.46%Salamander Energy (SMDR) 177.90p -7.87%Anglo Pacific Group (APF) 258.70p -6.54%Ferrexpo (FXPO) 293.30p -6.05%Thomas Cook Group (TCG) 36.48p -6.00%Brewin Dolphin Holdings (BRW) 120.60p -6.00% Tesco Centrica 3i Group