Mining heavyweights Antofagasta, Rio Tinto, ENRC and BHP Billiton were all registering steep losses after Credit Suisse slashed target prices across the sector after lowering commodity price estimates. Rio Tinto announced this morning that its Chief Financial Officer is to retire at the end of next year. While the miners were being weighed down by broker comments and global growth concerns, fund manager Ashmore was by far the worst performer on the Footsie, dropping nearly eight per cent after saying assets under management fell 3.3% to $63.7bn in the quarter ended June 30th as worries about the Eurozone crisis and global growth rattled investor confidence. Security giant G4S was another heavy faller on reports that it had encountered delays in training security staff for the Olympics. "We have encountered some delays in progressing applicants through the final stages but we are working extremely hard to process these as swiftly as possible," the firm said. Defence Secretary Philip Hammond is expected to announce details of an extra 3,500 troops to help with security for the Games today. Banking giant HSBC was also firmly lower after it was widely reported to be facing as much as a one billion dollar fine after it failed to ensure it had taken the appropriate steps to guard against the financing of terrorism and other criminal acitivity.Meanwhile, energy provider Centrica rose after it agreed to acquire the New York-based energy retailers Energetix and NYSEG Solutions, which operate as a single retail organisation, in order to strengthen its position in north-east America. Associated British Foods was also higher after reporting group revenue was 11% higher in the 40 weeks to June 23rd. FTSE 100 - RisersAdmiral Group (ADM) 1,185.00p +1.46%Associated British Foods (ABF) 1,279.00p +0.95%Capita (CPI) 686.00p +0.73%Resolution Ltd. (RSL) 210.40p +0.72%ITV (ITV) 72.25p +0.56%BP (BP.) 434.50p +0.45%Land Securities Group (LAND) 768.00p +0.33%Centrica (CNA) 319.50p +0.25%Reckitt Benckiser Group (RB.) 3,525.00p +0.23%British Sky Broadcasting Group (BSY) 685.50p +0.22%FTSE 100 - FallersAshmore Group (ASHM) 306.30p -7.18%Antofagasta (ANTO) 1,048.00p -3.23%Rio Tinto (RIO) 2,940.00p -3.07%Aggreko (AGK) 1,933.00p -3.01%Eurasian Natural Resources Corp. (ENRC) 400.10p -2.63%IMI (IMI) 787.50p -2.60%G4S (GFS) 282.90p -2.58%Glencore International (GLEN) 309.00p -2.31%HSBC Holdings (HSBA) 555.80p -2.27%BHP Billiton (BLT) 1,770.50p -2.24%NR