The mining sector is out of favour on Tuesday on the back of falling metals prices. Metals prices have continued to fall since the death of Al-Qaeda leader Osama Bin Laden yesterday, which triggered a sell-off in the 'safe-haven' investments of precious metals, as geopolitical anxieties eased.Weighing on silver prices is the US metals exchange's (Comex division of the New York Mercantile Exchange) announcement to raise the initial margin requirements on futures contracts, causing smaller investors to liquidate positions, analysts have suggested. Antofagasta, Kazakhmys and Randgold Resources are the three worst performing blue chips, all falling around 2.6% each.Miner BHP Billiton is also under the weather despite its partner in the Samarco project having approved the $3.5bn expansion plan for the joint venture, which is expected to increase iron ore pellet production capacity by 8.3m tonnes to 30.5m per annum. Meanwhile, hedge fund manager Man Group is the best performer of the day after it announced the launch of an AHL open-ended fund in Japan, Nomura Global Trend, which has raised $1.5bn. The fund began trading at the end of April 2011. IMI is higher after UBS said that 2011 is shaping up to be a "great year" for the engineer, raising its target price by a quarter. Also being helped by broker comments is pharmaceutical giant Shire, after Credit Suisse said that it expects the group to deliver the best sales growth (8% per annum) in its peer group over the next five years.---BCFTSE 100 - RisersMan Group (EMG) 258.00p +3.32%Autonomy Corporation (AU.) 1,647.00p +2.30%IMI (IMI) 1,116.00p +2.20%AstraZeneca (AZN) 3,049.00p +1.97%Johnson Matthey (JMAT) 2,042.00p +1.95%Burberry Group (BRBY) 1,316.00p +1.62%Unilever (ULVR) 1,969.00p +1.39%Reed Elsevier (REL) 537.00p +1.32%Intertek Group (ITRK) 2,152.00p +1.27%Imperial Tobacco Group (IMT) 2,133.00p +1.23%FTSE 100 - FallersAntofagasta (ANTO) 1,331.00p -2.63%Kazakhmys (KAZ) 1,343.00p -2.61%Randgold Resources Ltd. (RRS) 5,085.00p -2.59%Vedanta Resources (VED) 2,284.00p -1.76%BG Group (BG.) 1,506.50p -1.76%ITV (ITV) 74.75p -1.71%Marks & Spencer Group (MKS) 381.70p -1.62%Rolls-Royce Group (RR.) 631.50p -1.56%Eurasian Natural Resources Corp. (ENRC) 898.50p -1.43%BT Group (BT.A) 193.00p -1.43%