Anglo American, owner of jeweler De Beers, surged on Thursday as the mining giant cut its forecast for annual diamond production in order to avoid overproduction in the weaker diamond market.United Utilities, SSE and Centrica was making gains as investors sought refuge in defensive utility stocks.A number of heavyweight stocks were in the red after going ex-dividend, weighing on the Footsie, including Aggreko, Barratt Development, Glencore and Legal & General.Shares in credit checking company Experian advanced in the wake of overnight gains by credit card giant Visa.Coca-cola continued higher on Wednesday's news that revenues increased in the first quarter of the year, despite a decline in Diet Coke sales.Tesco recovered from Wednesday's losses, which were driven by record full-year losses of £6.4bn.BHP Billiton also rebounded from declines made of Wednesday, when the company announced that it would postpone plans to increase iron ore output.FTSE 100 - RisersRio Tinto (RIO) 2,929.00p +2.29%Anglo American (AAL) 1,036.50p +2.22%Ashtead Group (AHT) 1,163.00p +2.11%United Utilities Group (UU.) 991.50p +1.85%BHP Billiton (BLT) 1,505.00p +1.48%SSE (SSE) 1,589.00p +1.47%Antofagasta (ANTO) 760.50p +1.47%Barclays (BARC) 257.00p +1.46%Vodafone Group (VOD) 230.40p +1.27%Morrison (Wm) Supermarkets (MRW) 192.70p +1.21%FallersLegal & General Group (LGEN) 266.70p -3.79%Old Mutual (OML) 231.00p -2.74%Mondi (MNDI) 1,320.00p -2.44%Weir Group (WEIR) 1,762.00p -2.22%Sports Direct International (SPD) 617.50p -2.14%Glencore (GLEN) 295.95p -2.08%Johnson Matthey (JMAT) 3,404.00p -1.79%Aggreko (AGK) 1,643.00p -1.73%WPP (WPP) 1,574.00p -1.38%Barratt Developments (BDEV) 527.50p -1.31%