UK GAS-Within-day price down on oversupply, day-ahead up on weaker wind

Nov 1 (Reuters) - Prompt British wholesale gas prices were mixed on Wednesday, as an oversupplied system drove the within-day price lower, and expected lower wind output for Thursday boosted the day-ahead contract, traders said. * The within-day gas price was down 0.20 pence at 47.90 pence per therm by 0917 GMT. * Day-ahead gas rose by 0.50 pence to 48.00 pence per therm. * "Frankly I do not see so many bullish points, except the renewables," said a British gas trader for the day ahead price hike, adding that cooler European weather was affecting the curve. * Peak wind power generation is forecast at 6.0 gigawatts (GW) on Wednesday but expected to fall to 3.8 GW on Thursday, Elexon data showed. * Lower wind output typically results in higher demand for gas from power plants. * Gas supply from Norway to Britain on Wednesday matched Tuesday's high levels of 113 mcm/day. * Britain's gas system was oversupplied by 14 million cubic metres (mcm), with demand forecast at 228.1 mcm and supply at 242.1 mcm/day, National Grid (LSE: NG.L - news) data showed. * Average temperatures on Wednesday could reach 14 degrees Celsius in southern Britain and are expected to fall to 10 degrees by Sunday, data from Britain's Met Office showed. * The December gas contract was up 0.65 pence at 51.05 p/therm. * In the Dutch gas market, the day-ahead gas price at the TTF hub rose by 0.20 euro to 18.10 euros per megawatt hour (MWh). * The benchmark Dec (Shanghai: 600875.SS - news) -17 EU carbon contract grew by 0.10 euro to 7.47 euros a tonne. * Thomson Reuters (Dusseldorf: TOC.DU - news) analyst view: http://emea1.apps.cp.extranet.thomsonreuters.biz/cms/?pageid=united-kingdom-gas (Reporting by Lefteris Karagiannopoulos in Oslo, editing by Louise Heavens)