UK GAS-Prompt prices slip as supply outpaces demand

* Gas system oversupplied by 16 mcm

* Oil weighs on prices further along the curve

LONDON, July 8 (Reuters) - Prompt British natural gas prices fell on Friday as strong supplies outstripped demand.

Gas for within-day delivery fetched 33.60 pence per therm at 0914 GMT, down 0.45 pence from their last settlement.

Gas for day-ahead delivery slipped 0.30 pence to 33.90 pence per therm.

"Prompt contracts have opened lower this morning on the back of a long system. In turn, the oversupplied system has pressured the near curve, whilst further falls in oil prices overnight have weighed on the contracts further out," said Marcel Boonaert, head of gas trading at Wingas UK.

Britain's gas system was oversupplied by 16.1 million cubic metres (mcm), with demand forecast at 180.2 mcm and supply at 196.3 mcm, National Grid (LSE: NG.L - news) data showed.

Traders said expected imports of liquefied natural gas (LNG) into the country had also weighed on prices, with three tankers scheduled to arrive over the next seven days.

Temperatures in Britain are forecast to be above the seasonal norm at the weekend but will fall back towards or below the seasonal norm next week.

"With (Other OTC: WWTH - news) normal weather forecast to dominate over the next two weeks, prices are likely to trade in a reasonably flat manner week-on-week," said analysts at UK-based consultancy Energy Aspects.

Gas prices on the curve also moved lower.

The Winter 16 contract fell 0.40 pence to 44.65 pence per therm.

Benchmark Brent crude oil futures fell 5 percent and hit two month lows on Thursday but regained some lost ground to trade over $46.70 a barrel on Friday morning.

In the Netherlands, the day-ahead gas price at the TTF hub was 0.3 euros lower at 14.00 euros per megawatt-hour (MWh).

In Europe's carbon market the front-year EU Allowance (EUA) price slipped 0.12 euro to 4.46 euros per tonne. (Reporting by Susanna Twidale; editing by Nina Chestney)