Engineering consultancy AMEC gained after saying it was trading in line with expectations despite ongoing economic uncertainty. The firm said mining activity was slowing, but conventional oil and gas activity remained strong, particularly in the North Sea and Gulf of Mexico. Shares in Centrica rose as the shares recovered from serious declines the previous day when it was forced to deny claims it had a hand in the manipulation of wholesale gas prices. Investigations are underway by the Financial Services Authority (FSA) and Ofgem following claims by a whistleblower. They centre on the claim that on 28th September - when information was being gathered to determine wholesale gas prices - traders made unrealistic bids to bolster their own positions. Energy supplier SSE was in demand after posting a 38% jump in profits in the first half as it immediately moved to offset a media storm over its hike in household bills last month. The firm pushed up its dividend 5% to 25.2p as earnings per share leapt 40.6% to 35.3p. Mining and oil stocks were the heaviest fallers on the Footsie throughout Wednesday, hit by concerns about the global economy: ENRC and Randgold were among the worst performers. The latter announced this morning that it has raised its stake in the North Sea Schiehallion field, at the same time as selling its interest in the Seal are in Canada. Evraz, the steel, mining and vanadium group, is the top faller of the day after proposing that a covenant be removed relating to $577m of outstanding guaranteed notes due 2015. Evraz is seeking to remove a covenant requiring the company to maintain the net leverage ratio at or below a specified level. The statement from the company stressed that it is not actually in breach of this covenant or any of the others, but the market still took fright at the news. Supermarket group Sainsbury was falling despite reporting a better-than-expected underlying half-year profit before tax as it continued to outperform in a challenging market. Retail peer Marks & Spencer was also lower after going ex-dividend.FTSE 100 - RisersAmec (AMEC) 1,058.00p +2.42%Centrica (CNA) 316.90p +1.96%Bunzl (BNZL) 1,043.00p +1.26%SSE (SSE) 1,400.00p +1.23%Pennon Group (PNN) 673.00p +1.13%Capita (CPI) 730.00p +1.11%Serco Group (SRP) 550.50p +1.01%United Utilities Group (UU.) 653.00p +0.85%Severn Trent (SVT) 1,542.00p +0.85%Weir Group (WEIR) 1,750.00p +0.69%FTSE 100 - FallersEvraz (EVR) 215.40p -7.87%Eurasian Natural Resources Corp. (ENRC) 274.70p -5.14%Randgold Resources Ltd. (RRS) 6,605.00p -4.69%Vedanta Resources (VED) 1,047.00p -3.94%Kazakhmys (KAZ) 660.00p -3.37%Burberry Group (BRBY) 1,196.00p -2.84%GKN (GKN) 202.00p -2.74%Royal Dutch Shell 'B' (RDSB) 2,166.00p -2.72%CRH (CRH) 1,110.00p -2.63%Sainsbury (J) (SBRY) 338.20p -2.59%NR