UK GAS-Prompt prices slightly down on oversupply

LONDON, April 5 (Reuters) - British prompt wholesale gas prices declined slightly on Wednesday morning due to oversupply. * Within-day contract down 0.10 pence at 40.80 pence per therm at 0854 GMT. * British day-ahead gas price inched down by 0.05 pence to at 40.80 p/therm. * System slightly oversupplied by around 9 million cubic metres (mcm), with demand forecast at 254 mcm and flows at 263 mcm/day, National Grid (LSE: NG.L - news) data shows. * Langeled flows are at 45 mcm, likely due to an outage at Norway's Kvitebjorn gas field which has reduced Norwegian exports by around 10 mcm. * Exports to continental Europe through the InterconnectorUK (IUK) are nominated at 41 mcm. * This might drop slightly over the next few days. "However, there is a reasonable possibility this will not happen with (UK gas) prices being kept in the current range by flexibility from LNG and storages, thereby enabling IUK to stay strong," said Oliver Sanderson, gas analyst at Thomson Reuters (Dusseldorf: TOC.DU - news) . * Peak wind generation at 5.6 gigawatts (GW) on Wednesday, falling to around 2.9 GW on Thursday, which could lift demand from gas-fired power plants, analysts said. * Winter 2017 contract edged up by 0.05 pence to 46.85 p/therm * Day-ahead gas price at the Netherlands' TTF hub up 0.08 euro at 16.13 euros per megawatt hour. * Benchmark Dec-17 EU carbon contract up 0.06 euro at 4.71 euros a tonne. * Thomson Reuters analyst view: http://emea1.apps.cp.extranet.thomsonreuters.biz/cms/?pageid=united-kingdom-gas (Reporting by Nina Chestney)