UK GAS-Prices mostly down due to ample supply

LONDON, April 12 (Reuters) - British wholesale gas prices were mostly lower on Thursday morning due to robust supply.

* Within-day contract down by 1.00 pence to at 52.50 p/therm at 0843 GMT

* "There looks to be ample supply today," a gas trader said

* Britain's system almost balanced with demand forecast at 257 million cubic metres (mcm) and flows at 256.6 mcm/day, National Grid data showed.

* Further out on the curve prices also slipped.

* May contract down 0.11 p at 49.70 p/therm.

* Winter 2018 contract down 0.25 p at 55.25 p/therm

* However, the day-ahead gas price inched up by 0.35 pence to 52.10 p/therm

* Traders said the day-ahead price was lifted due to an expectation of strong demand from gas-fired power stations as output from the country's wind farms is forecast to fall on Friday.

* "Day-ahead gas for power demand is 5 up mcm (million cubic meters)," analysts at Thomson Reuters (Dusseldorf: TOC.DU - news) said in a daily research note.

* Peak wind power generation is forecast at 5.9 gigawatts (GW) on Thursday, falling to 3.6 GW on Friday, National Grid (LSE: NG.L - news) data showed.

* In the Dutch gas market, the day-ahead gas price at the TTF hub up 0.17 euro at 19.70 euros per megawatt-hour.

* Benchmark Dec-18 EU carbon contract down 0.08 euro at 13.35 euros per tonne.

* Thomson Reuters analyst view:http://emea1.apps.cp.extranet.thomsonreuters.biz/cms/?pageid=united-kingdom-gas (Reporting by Susanna Twidale; editing by Nina Chestney)