- Support for New Democracy increases- Some European, US markets closed today- Miners gain on increased risk appetiteLondon's blue-chip index advanced in early trading on Monday as sentiment improved on the back of the polls in Greece which showed that the pro-bailout party was in the lead.Several opinion polls published this weekend showed that pro-bailout party New Democracy as the favourite to win the elections in Greece on June 17th. Specifically, five separate polls show New Democracy leading by a margin of 0.5 to 5.7 points. This would put the group ahead of the radical left wing Syriza party that opposes the terms the second bailout signed with the "troika" (name given to the combination of the EU, the IMF and the ECB). Equity markets are closed in Austria, Denmark, Hungary, Norway, Switzerland and the US today for a bank holiday. This, combined with no major economic releases, could see small gains in stocks and the euro, according to analyst Craig Erlam from Alpari. "This could also lead to some gains in precious metals and oil, however the latter may be limited given the high supply and falling demand currently being experienced at the moment," he said.FTSE 100: Miners advance early onThe mining sector was making strong gains in the opening hour of trade today as rising metals prices and increased risk appetite gave a lift to stocks. Polymetal, Rio Tinto, Antogasta, Vedanta, Kazakhmys, Xstrata and Fresnillo were among the best performers.Guiness owner Diageo was in demand after saying that it is set to buy Ypioca, one of Brazil's largest cachaca brands in Brazil, for £300m in cash. "The acquisition of Ypioca gives us the leading premium brand in the largest local spirits category. It will also provide Diageo with an enhanced platform from which to accelerate the long term growth of our premium international spirits brands in Brazil," said Diageo's Chief Executive Officer Paul Walsh.Rolls-Royce, the global power systems company, was also higher after saying it has secured contract extensions with the Royal Air Force worth almost £100m.Tullow Oil was on the up after announcing late Friday that its Ngamia-1 well in Kenya was making good progress. After letting slip to investors at a meeting, the company was prompted to release a statement saying that drilling into the primary target and that initial results showed that it had intersected further oil bearing sands.FTSE 250: Inmarsat rises after upgradeSatellite group Inmarsat was a high riser on the second-tier index after Jefferies upgraded its rating on the stock from hold to buy, saying that it now has greater visibility on the issues cited behind the August 2011 profit warnings. "The downgrade cycle looks to have ended and further signs of top-line stabilisation should see further re-rating (Inmarsat's forward PE has halved from its peak, though recovered since profit warning)." The target price was hiked from 425p to 555p.The engineering software company, AVEVA, reported record profits for the 12 months ended March 21st as the firm capitalised on growing demand from deep-water oil and gas exploration. Shares advanced strongly early on.Salamander Energy, the upstream oil and gas company focused on Thailand and Indonesia, rose after announcing a successful appraisal of the Tutung gas-condensate discovery in Indonesia. Global equity investment group Scottish Investment Trust rose after saying that returns outpaced its benchmarks in half year ended April 30th despite the economic uncertainty that has gripped stock markets in recent months.FTSE 100 - RisersPolymetal International (POLY) 827.50p +3.31%Capita (CPI) 628.50p +2.86%Rio Tinto (RIO) 2,871.00p +2.72%ARM Holdings (ARM) 504.00p +2.61%Antofagasta (ANTO) 1,042.00p +2.46%GKN (GKN) 187.20p +2.41%Vedanta Resources (VED) 989.00p +2.33%Kazakhmys (KAZ) 695.00p +2.21%Weir Group (WEIR) 1,585.00p +2.13%IMI (IMI) 898.50p +2.10%FTSE 100 - FallersInternational Consolidated Airlines Group SA (CDI) (IAG) 137.60p -2.34%Kingfisher (KGF) 276.30p -1.29%Resolution Ltd. (RSL) 201.20p -0.59%National Grid (NG.) 681.00p -0.51%Severn Trent (SVT) 1,694.00p -0.41%Centrica (CNA) 311.70p -0.32%SSE (SSE) 1,357.00p -0.15%International Power (IPR) 413.90p -0.02%FTSE 250 - RisersInmarsat (ISAT) 420.00p +4.87%Avocet Mining (AVM) 150.20p +4.82%JD Sports Fashion (JD.) 739.00p +4.67%Northgate (NTG) 183.90p +4.49%Aveva Group (AVV) 1,544.00p +4.25%Cape (CIU) 213.00p +3.90%Ferrexpo (FXPO) 214.20p +3.78%Dixons Retail (DXNS) 14.50p +3.65%Ruspetro (RPO) 153.90p +3.57%Hochschild Mining (HOC) 417.50p +3.01%FTSE 250 - FallersBarr (A.G.) (BAG) 362.50p -0.96%Jardine Lloyd Thompson Group (JLT) 675.00p -0.88%Rank Group (RNK) 119.80p -0.58%Home Retail Group (HOME) 76.75p -0.52%UBM (UBM) 525.00p -0.47%Brewin Dolphin Holdings (BRW) 142.00p -0.35%Drax Group (DRX) 559.00p -0.27%Rathbone Brothers (RAT) 1,185.00p -0.25%Phoenix Group Holdings (DI) (PHNX) 438.90p -0.23%Kesa Electricals (KESA) 47.63p -0.19%BC