Fresnillo led miners higher on Wednesday after reporting a rise in second quarter production of silver, driven by a ramp-up at Saucito and increased volumes milled at Ciénega.BHP Billiton's shares surged after saying its half-year profit and revenue climbed on the back of an increase in production across all operations.Glencore Xstrata rallied a day after announcing it had started the sale process of its Las Bambas copper project in Peru. The decision is in line with conditions set out by China's anti-trust regulator when it approved the multi-billion-dollar merger that created the commodities giant in April.Engineering company Smiths Group, on the other hand, slumped after saying its headline operating profit for the full-year was likely to be £15m below current expectations, reflecting contractual issues in its Detection unit. Imperial Tobacco Group retreated after analysts at Natixis downgraded the company's stock to a 'neutral' rating in a note on Wednesday.Johnson Matthey edged lower after Credit Suisse cut its rating of the chemicals and precious metals company's shares to 'neutral' from 'outperform'. FTSE 100 - RisersFresnillo (FRES) 1,050.00p +3.35%BHP Billiton (BLT) 1,869.50p +2.05%Glencore Xstrata (GLEN) 269.90p +2.02%Anglo American (AAL) 1,348.00p +1.81%Tesco (TSCO) 361.00p +1.55%Antofagasta (ANTO) 844.50p +1.38%Tullow Oil (TLW) 1,106.00p +1.28%Smith & Nephew (SN.) 782.00p +1.16%Rio Tinto (RIO) 2,915.50p +1.13%Rexam (REX) 491.50p +1.03%FTSE 100 - FallersSmiths Group (SMIN) 1,355.00p -2.59%Imperial Tobacco Group (IMT) 2,199.00p -2.40%Johnson Matthey (JMAT) 2,751.00p -1.96%Serco Group (SRP) 613.50p -1.92%Land Securities Group (LAND) 951.50p -1.86%Capita (CPI) 1,039.00p -1.52%Unilever (ULVR) 2,760.00p -1.50%Amec (AMEC) 1,052.00p -1.41%Admiral Group (ADM) 1,372.00p -1.29%ITV (ITV) 154.40p -1.28%