Good news for Tullow Oil sent its share price soaring after its joint venture with Royal Dutch Shell has made an oil discovery at its Zeadyus exploration well, 150km offshore French Guiana.The Guyana Maritime permit said it has encountered 72m of net oil pay in two turbidite fans, and the results of drilling and sampling show "good quality reservoir sands on prognosis." Motor insurer Admiral took a hit after admitting that it could see "a small proportion" of its profits put at risk under the government's plans to ban the payment of referral fees to insurers.The Ministry of Justice (MoJ) announced on Friday that it plans to tackle rising insurance costs by placing abolishing the fees, as part of its commitment to curb 'compensation culture'. FTSE 100 - RisersTullow Oil (TLW) 1,371.00p +11.74%Fresnillo (FRES) 2,209.00p +2.89%Imperial Tobacco Group (IMT) 2,094.00p +1.65%Essar Energy (ESSR) 264.10p +1.54%Randgold Resources Ltd. (RRS) 7,110.00p +0.99%British Sky Broadcasting Group (BSY) 674.50p +0.82%British American Tobacco (BATS) 2,782.50p +0.72%Petrofac Ltd. (PFC) 1,395.00p +0.72%Morrison (Wm) Supermarkets (MRW) 303.10p +0.50%Amec (AMEC) 921.50p +0.33%FTSE 100 - FallersAdmiral Group (ADM) 1,292.00p -5.28%Royal Bank of Scotland Group (RBS) 21.71p -4.53%Barclays (BARC) 151.85p -4.50%Lloyds Banking Group (LLOY) 31.48p -4.30%International Consolidated Airlines Group SA (IAG) 156.40p -3.58%GKN (GKN) 182.80p -2.87%Vedanta Resources (VED) 1,412.00p -2.69%Man Group (EMG) 223.30p -2.53%Aviva (AV.) 312.70p -2.52%Hammerson (HMSO) 390.70p -2.25%NR