Stocks are posting big gains as investors pin their hopes on the Greek parliament voting in favour of austerity measures later today.Most excitement is in the FTSE 250, with Charter International now the top riser the engineer Melrose said it had approached its rival about making a 780p offer yesterday.Senior is another strong riser after saying it expects pre-tax profit for the six months ended 30 June to be ahead of previous expectations, driven by the recovery in the truck markets and increased production in its Aerospace Division.UK-listed oil producer Exillon Energy gushed higher after preliminary results from Exploration Well 4 in West Siberia confirmed the presence of 6.7m of effective net oil pay in a new area.Bus and train group Stagecoach said sales of £2.39bn came in short of expectations of £2.47bn.Betfair, the betting exchange that has been rocked by a number of departures by high ranking executives, said full year profitability came in ahead of expectations, though it conceded revenue growth "could have been stronger". Shares were flat early on.International energy services firm Hunting edged higher after saying it remains confident that trading will be in line with expectations for year ending 31 December 2011.Shares in lighting, power and electronics system manufacturer LPA raced ahead after it said it had won a contract to upgrade control panels used by drivers on trains operating in the southeast of England. The contract is worth £300,000. It will begin this financial year and complete early next year, said LPA, which has not said who it won the contract with. FTSE 100 - RisersICAP (IAP) 464.00p +6.30%Antofagasta (ANTO) 1,362.00p +4.53%Barclays (BARC) 252.75p +4.46%Legal & General Group (LGEN) 115.40p +3.96%Eurasian Natural Resources Corp. (ENRC) 759.00p +3.69%IMI (IMI) 1,032.00p +3.67%GKN (GKN) 227.90p +3.50%Burberry Group (BRBY) 1,424.00p +3.34%Kazakhmys (KAZ) 1,341.00p +3.15%Smiths Group (SMIN) 1,182.00p +2.87%FTSE 100 - FallersMarks & Spencer Group (MKS) 361.80p -1.92%Kingfisher (KGF) 265.40p -1.56%Compass Group (CPG) 594.50p -1.16%Reckitt Benckiser Group (RB.) 3,397.00p -0.93%Tate & Lyle (TATE) 614.50p -0.65%Scottish & Southern Energy (SSE) 1,381.00p -0.36%British Sky Broadcasting Group (BSY) 847.50p -0.18%Next (NXT) 2,273.00p -0.13%RSA Insurance Group (RSA) 132.50p -0.08%Serco Group (SRP) 551.50p +0.18%FTSE 250 - RisersCharter International (CHTR) 775.00p +26.02%Senior (SNR) 175.80p +8.18%Exillon Energy (EXI) 432.30p +8.02%Bwin.party Digital Entertainment (BPTY) 143.50p +7.89%Talvivaara Mining Company (TALV) 434.00p +5.91%Melrose (MRO) 365.00p +5.89%Cookson Group (CKSN) 651.50p +5.76%Ashtead Group (AHT) 168.10p +5.06%Cable & Wireless Worldwide (CW.) 47.03p +4.51%Morgan Crucible Co (MGCR) 300.20p +4.42%FTSE 250 - FallersPremier Foods (PFD) 24.59p -3.87%Halfords Group (HFD) 379.10p -2.39%Cranswick (CWK) 731.50p -2.27%Kenmare Resources (KMR) 56.65p -1.65%Dunelm Group (DNLM) 393.00p -1.50%Homeserve (HSV) 502.00p -1.47%JD Sports Fashion (JD.) 907.50p -1.36%Fidessa Group (FDSA) 1,930.00p -1.18%Stobart Group Ltd. (STOB) 141.50p -1.12%Carpetright (CPR) 661.00p -0.97%