Babcock International Group was the top riser on Monday after confirming the UK government has chosen the engineering company to manage the decommissioning of 12 nuclear sites. Rio Tinto and Anglo American gained after Credit Suisse named the companies as its top picks in the metals and mining sector.ITV advanced after signing up to the Twitter Amplify service to helps brands extend TV advertising campaigns across social media.Insurance stocks continued to be in focus after the reported regulatory investigation into the industry. St. James's Place was the biggest faller after the wealth manager joined the FTSE 100 last week, while Aviva and Resolution rose after some sharp falls on Friday.SSE slumped after the British energy supplier said last week that it will freeze household electricity and gas prices until 2016.GlaxoSmithKline declined after the pharmaceutical giant said the third phase of its study of darpladib failed to meet its target for the prevention of stroke.FTSE 100 - RisersBabcock International Group (BAB) 1,348.00p +4.33%Mondi (MNDI) 1,060.00p +3.31%Rio Tinto (RIO) 3,355.00p +2.30%ITV (ITV) 193.60p +2.22%ARM Holdings (ARM) 999.00p +2.20%Aviva (AV.) 478.20p +1.70%Anglo American (AAL) 1,534.50p +1.69%G4S (GFS) 241.60p +1.56%Resolution Ltd. (RSL) 300.90p +1.55%Petrofac Ltd. (PFC) 1,436.00p +1.41%FTSE 100 - FallersSt James's Place (STJ) 828.00p -1.90%SSE (SSE) 1,484.00p -1.79%Shire Plc (SHP) 2,979.00p -1.39%Sports Direct International (SPD) 855.00p -1.27%GlaxoSmithKline (GSK) 1,602.50p -0.96%National Grid (NG.) 823.00p -0.84%Smith & Nephew (SN.) 914.50p -0.76%Standard Life (SL.) 377.60p -0.71%United Utilities Group (UU.) 791.00p -0.69%Land Securities Group (LAND) 1,028.00p -0.58%RD