UK GAS-Prompt prices slip as warm weather curbs demand

LONDON, May 23 (Reuters) - Prompt British wholesale gas prices edged lower on Tuesday morning, as warm temperatures curbed demand, leaving the system oversupplied. * British day-ahead gas price was down 1.10 pence at 36.30 pence per therm at 0844 GMT. * Within-day contract was down 0.75 pence at 36.50 p/therm. * Gas system oversupplied by 15.1 million cubic meters (mcm), with demand forecast at 192.9 mcm/day and flows at 208 mcm/day, National Grid (LSE: NG.L - news) data showed. * Traders said forecasts for warm weather and high output from the country's nuclear power stations led to weak gas demand, pressuring prices. * Gas demand almost 9 percent below seasonal norm of 212 mcm, National Grid data showed. * Britain's Met Offices forecast temperatures could reach around 24 degrees Celsius in the southeast of the country on Wednesday, and possibly hit as high at 30 degrees at the weekend. * All but one of Britain's 15 nuclear reactors were in operation on Tuesday, National Grid data showed, providing around 25 percent of the country's electricity supplies. * June gas contract was down 0.40 pence at 36.05 p/therm. * Winter 2017 contract was down 0.36 pence at 45.85 p/therm. * Day-ahead gas price at the Dutch TTF hub was down 0.05 euro at 15.20 euros per megawatt hour. * Benchmark Dec-17 EU carbon contract was down 0.01 euro at 4.91 euros per tonne. * Thomson Reuters (Dusseldorf: TOC.DU - news) analyst view: http://emea1.apps.cp.extranet.thomsonreuters.biz/cms/?pageid=united-kingdom-gas (Reporting by Susanna Twidale, editing by Louise Heavens)