UK GAS-Spot price pressured by storage flows, oversupply

March 8 (Reuters) - British spot gas prices fell on Thursday as strong output from mid-range storage sites contributed to an oversupplied system.

* Within-day gas was down 0.6 pence at 51 pence per therm (p/therm) by 0958 GMT.

* Day-ahead gas rose by 0.4 pence to 51.50 p/therm, reflecting the chance of cooler weather and low stored reserves.

* The system was oversupplied by 11.8 million cubic metres (mcm) early on Thursday, National Grid (LSE: NG.L - news) data showed, with demand at 312.8 mcm/day and supply at 324.6 mcm/day.

* Expected daily withdrawal from British storage sites was at 35 mcm as residential and commercial demand weakened and UK Continental Shelf output was expected to improve, reinforcing bearish sentiment.

* A fresh liquefied natural gas (LNG) delivery from Qatar is due to arrive at South Hook in Milford Haven, Wales, on March 24, signalling a pick-up in shipments on top of the two tankers already in-bound.

* An unplanned reactor outage at Heysham 2-8 helped to support day-ahead baseload UK power prices, up 2 pounds to 53 pounds per megawatt-hour (MWh).

* Norwegian flows to the UK rose by 10 mcm/day to 130mcm/day, figures from Norwegian pipeline operator Gassco showed.

* The April contract rose by 0.39 pence to 48.47 p/therm.

* Day-ahead gas at the Dutch TTF hub was unchanged at 18.80 euros/MWh.

* The benchmark Dec (Shanghai: 600875.SS - news) -18 EU carbon contract edged 0.08 euros higher to 10.72 euros a tonne.

* Thomson Reuters (Dusseldorf: TOC.DU - news) analyst view: http://emea1.apps.cp.extranet.thomsonreuters.biz/cms/?pageid=united-kingdom-gas. (Reporting by Oleg Vukmanovic Editing by David Goodman)