UK GAS-Within-day price falls as pipeline shuts, weather curbs demand

LONDON, June 14 (Reuters) - The within-day British wholesale gas price fell on Wednesday morning, as warm weather curbed demand and the closure of a major gas pipeline with mainland Europe cut off an export route for surplus gas. * British within-day gas price down by 0.55 pence at 32.20 pence/therm by 0743 GMT. * "IUK maintenance is the primary bearish driver," said Katrina Oldham, an energy trader at Inenco. * The Interconnector UK (IUK) pipeline between Britain and Belgium will close for annual maintenance from June 14 until June 29. * British gas system oversupplied by 5.5 million cubic metres (mcm), with demand forecast at 158.6 mcm and flows at 164.1 mcm/day, National Grid (LSE: NG.L - news) data showed. * Britain's Met Office said temperatures could reach 28 degrees Celsius in the south of the country on Wednesday and could hit 30 degrees over the weekend. * Wednesday's gas demand was 22 percent lower than the seasonal norm of 203 mcm, National Grid data showed. * Warm temperatures also dented demand for electricity. Day-ahead wholesale electricity contract was down by 3.2 pounds at 34.05 pounds/ per megawatt hour (MWh). * July gas contract was up by 0.02 pence at 35.50 p/therm. * Day-ahead gas price at the Dutch TTF hub was up by 0.02 euro at 15.20 euros/MWh. * Benchmark Dec-17 EU carbon contract up by 0.04 euro at 5.05 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)