London open: FTSE 100 on the slide again

Shares are firmly in the red again today, with miners on the slide in line with commodity markets and one or two trading updates setting traders' nerves on edge.Silver specialist Fresnillo leads the mining sector lower in the FTSE 100. Worries that China may further tighten monetary policy are hurting commodity prices.Telecoms giant BT saw underlying profit before tax surge 21% in the final quarter of its financial year (Q1 2011) from a year earlier, despite revenue easing 6% year on year. The full year dividend has been hiked 7% to 7.4p. But the stock is one of the poorest performers in the FTSE 100 today.Oil and gas firm Tullow is another struggler today, even after it said it has performed very strongly so far in 2011, with "excellent results" from its drilling programme in Ghana, while significant progress has been made in Uganda. But the FTSE 250 that is seeing the biggest falls. Fast-growing fashion group SuperGroup failed to get its summer range out in time for the unseasonably warm weather seen recently, resulting in a lower sales growth rate in the three months to 1 May. The company, best known for the Superdry label, said total sales were up by 61% from the same period a year ago at £66m. The fourth quarter growth rate was lower than the 71% rise seen in the full year to 1 May, during which retail and wholesale sales climbed by 71%.A profit warning from Keller has the ground engineering specialist firmly in the red. "There has not been any meaningful recovery in our construction markets in the US and Western Europe, which were most severely impacted by the global recession," Keller said in a company statement. Dixons Retail has maintained its profit forecast for the year to 30 April, despite continued tough trading at the PC World and Curry's owner. In March, the firm said underlying pre-tax profits for the year would be about £85m, having previously indicated they would be above £100m. The latest forecast has been maintained, despite second half sales falling by 4% from the same period a year ago, against a 2% decline over the full year. RSA Insurance hailed a strong start to the year with net written premiums of £2.1bn in the first quarter, up 8% on a year earlier. All regions delivered good growth. The group remains confident of delivering full year premium growth of around 10% in International, targeted growth in the UK and double digit growth in emerging markets.Levels of client advertising and research expenditure have picked up in 2011 and Aegis Group, which is bucking the downward trend today expects this trend to continue for the rest of the year. The media buying and market research agency expects organic revenue growth for 2011 to be at least in line with the level achieved last year "in spite of the more difficult comparatives for the remainder of the year." 3i leads the risers in the FTSE 100. The private equity group said investment increased to £719 million in the year to 31 March, up from £386m in 2010.FTSE 100 - Risers3i Group (III) 286.30p +5.37%Scottish & Southern Energy (SSE) 1,375.00p +1.78%International Consolidated Airlines Group SA (IAG) 250.00p +1.46%Royal Bank of Scotland Group (RBS) 42.88p +1.08%Barclays (BARC) 281.05p +0.72%AstraZeneca (AZN) 3,163.00p +0.65%TUI Travel (TT.) 246.50p +0.57%Shire Plc (SHP) 1,932.00p +0.52%Carnival (CCL) 2,602.00p +0.46%Reed Elsevier (REL) 562.00p +0.45%FTSE 100 - FallersFresnillo (FRES) 1,362.00p -3.47%ICAP (IAP) 493.50p -3.14%Old Mutual (OML) 131.50p -2.81%Eurasian Natural Resources Corp. (ENRC) 838.50p -2.73%Kazakhmys (KAZ) 1,231.00p -2.69%Lonmin (LMI) 1,513.00p -2.45%Anglo American (AAL) 2,920.50p -2.36%Xstrata (XTA) 1,379.00p -2.20%BHP Billiton (BLT) 2,355.50p -2.10%Antofagasta (ANTO) 1,164.00p -2.10%FTSE 250 - RisersFirstGroup (FGP) 366.80p +4.26%Avis Europe (AVE) 199.90p +3.04%National Express Group (NEX) 268.50p +2.09%Ocado Group (OCDO) 215.10p +1.94%Informa (INF) 434.00p +1.78%Aegis Group (AGS) 141.60p +1.58%Cable & Wireless Worldwide (CW.) 52.50p +1.16%Stobart Group Ltd. (STOB) 135.60p +1.12%Stagecoach Group (SGC) 246.70p +1.11%easyJet (EZJ) 360.90p +1.06%FTSE 250 - FallersKeller Group (KLR) 505.00p -23.60%Supergroup (SGP) 1,300.00p -17.41%Tullett Prebon (TLPR) 395.90p -5.17%Kenmare Resources (KMR) 44.23p -2.90%Aquarius Platinum Ltd. (AQP) 334.60p -2.45%Sports Direct International (SPD) 205.30p -2.24%Cookson Group (CKSN) 706.00p -2.22%Hochschild Mining (HOC) 531.00p -2.03%BlackRock World Mining Trust (BRWM) 745.55p -1.77%EnQuest (ENQ) 134.00p -1.76%---RG