Shares in ICAP fell over six per cent on Wednesday after the interdealer broker published a trading statement showing that trading conditions for the nine months ended December 31st 2012 were "extremely challenging". It said that group revenue for the year ending March 31st 2013 is expected to be 13% below the previous year.The company's Chief Executive Michael Spencer said: "While we had a better start to the fourth quarter, we are not yet seeing a sustained upturn with market activity remaining fragile and unpredictable."Gold mining group Centamin's share price slid despite saying that full-year production increased by nearly a third in 2012 while EBITDA jumped 10%.Independent oil and gas production company EnQuest was among the biggest risers with shares up 2.5% at the close of trading after its 2012 results. Revenues fell 5.0% last year due to declining production, but profits grew 3.8% due to cost control and strong operational performance.FTSE 250 - RisersOcado Group (OCDO) 160.70p +3.68%United Drug (UDG) 273.20p +3.09%Domino's Pizza Group (DOM) 602.50p +2.64%EnQuest (ENQ) 143.80p +2.49%COLT Group SA (COLT) 129.50p +2.37%Dixons Retail (DXNS) 33.69p +2.09%St. Modwen Properties (SMP) 256.40p +1.75%Fenner (FENR) 391.70p +1.58%African Barrick Gold (ABG) 206.60p +1.57%Restaurant Group (RTN) 466.90p +1.52%FTSE 250 - FallersICAP (IAP) 302.50p -6.23%Centamin (DI) (CEY) 53.75p -4.44%Synthomer (SYNT) 212.30p -4.37%Carillion (CLLN) 273.80p -4.06%Hochschild Mining (HOC) 286.90p -3.72%Rathbone Brothers (RAT) 1,434.00p -3.69%Greene King (GNK) 692.50p -3.62%Cranswick (CWK) 983.50p -3.29%Man Group (EMG) 90.60p -3.26%Vesuvius (VSVS) 352.80p -3.24%MF