UK GAS-Prices jump as European supplies dwindle, demand stays high

LONDON, March 20 (Reuters) - British wholesale gas prices jumped almost 10 percent on Tuesday as supplies from Europe dwindled just as demand remained above average following an unseasonable cold snap.

* Within-day gas was up 4.5 pence at 58.50 pence per therm at 0840 GMT, having risen 9.3 percent in earlier trading.

* Day-ahead prices were up 1.35 pence at 56.00 p/therm.

* Flows along the IUK interconnector from Belgium were nominated at 6 million cubic metres (mcm); physical flows on Tuesday morning showed they were down 33 mcm.

* Flows along the BBL Interconnector from the Netherlands were down 9 mcm and an outage along the Vesterled pipeline reduced imports from Norway by 6 mcm.

* "MRS (medium-range storage) does not have much flexibility with record lowest stocks after the cold end of winter and so the market will price the gas needed today," Thomson Reuters (Dusseldorf: TOC.DU - news) analyst Katarzyna Piaskowska said.

* "Particularly low IUK and BBL (Shenzhen: 002776.SZ - news) nominations probably mean the Continent supply will wait for substantially higher spreads as well".

* The UK market is expected to be undersupplied for the day by 12.4 mcm, with demand of 337 mcm outstripping predicted flows of 324.6 mcm.

* Snow and freezing temperatures covered parts of Britain in recent days and gas demand remained stubbornly high -- 23 percent above average for Tuesday.

* Temperatures are expected to average 3.1 degrees Celsius on Tuesday and on Wednesday, according to weather forecasts followed by Thomson Reuters.

* Day-ahead gas at the Dutch TTF hub rose 0.35 euro to 21.00 euros per megawatt hour.

* The benchmark Dec (Shanghai: 600875.SS - news) -18 EU carbon contract fell 0.03 euro to 11.03 euros a tonne.

* Thomson Reuters analyst view: http://emea1.apps.cp.extranet.thomsonreuters.biz/cms/?pageid=united-kingdom-gas. (Reporting by Sabina Zawadzki, editing by Louise Heavens)