UK GAS-Prices fall on ample supply

* System oversupplied by 15 mcm/day

* Flows through Langeled resume

Aug 31 (Reuters) - British wholesale gas prices fell on Wednesday due to ample supplies of gas.

Gas for day-ahead delivery fell by 0.90 pence to 25.60 pence per therm at 0851 GMT, while the within-day contract was 1.10 pence lower at 25.75 p/therm.

"Supply is still strong. Perhaps prices would have been even lower if it wasn't for high export levels," a UK gas trader said.

Britain's gas system was oversupplied by around 15 million cubic metres/day (mcm). Demand was forecast to be around 184 mcm while flows were just over 199 mcm/day, National Grid (LSE: NG.L - news) data shows.

Flows from Norway through the Langeled pipeline were at 5 mcm as it returned to service after a shutdown.

UK Continental Shelf flows were healthy at 146 mcm and there should be high liquefied natural gas stock levels in September and a good frequency of LNG cargo arrivals.

Exports to continental Europe are at a record high as high storage levels incentivise exporting gas.

Further along the curve, the September contract , which expires by Thursday, was down 0.60 pence at 28.15 pence per therm.

In the Dutch gas market, the day-ahead price at the TTF hub was 0.20 euro lower at to 11.60 euros per megawatt-hour.

European front-year carbon allowances inched down by 0.02 euro to 4.53 euros a tonne. (Reporting by Nina Chestney)