UK GAS-Prices extend fall on oversupply after two-week bounce

LONDON, July 17 (Reuters) - British wholesale gas prices fell on Wednesday, extending this week's losses after a prolonged rise since the start of the month, thanks to an oversupplied market.

* Day-ahead gas price was down by 0.3 pence at 30.75 pence per therm at 0755 GMT.

* Within-day gas was down 1.25 pence to 31.00 p/therm.

* Both contracts rose around 50% in the first two weeks of July with several outages in Norway prompting price rises that were then compounded by short covering.

* An unplanned outage at Aasta Hansteen in Norway had been extended by two days but the impact was reduced to 11 million cubic metres (mcm) from 26 mcm.

* Another unplanned Norwegian outage, at Troll, will have an impact of 21 mcm on Wednesday but end by Thursday.

* The British gas system was oversupplied with demand forecast at 154.1 mcm and supply seen at 161.8 mcm, National Grid data showed.

* British contracts have been pulled down by Dutch gas prices, a benchmark for Europe, which fell on Tuesday as Russian gas flows through Slovakia surprised on the upside.

* The market had been expecting supply cuts via the Nord Stream pipeline to Europe from Russia due to maintenance.

* But those were offset by a large jump at the Velke Kapusany entry point to Europe to 2,150 gigawatt hours per day from 1,500 GWh/d, traders and gas analysts said.

* In Britain, peak wind generation is seen jumping to 5.6 gigawatts (GW) from 1.2 GW on Tuesday, which helps lower gas-for-power demand.

* Send-out from LNG terminals is expected to be relatively low compared to previous weeks, at 10 mcm.

* But another tanker declared for Britain on Wednesday, bringing the total to three LNG tankers due to arrive in the next eight days.

* In the Dutch gas market, the day-ahead price at the TTF hub continued its downward trend, falling 0.4 euro to 10.85 euros per megawatt hour.

* The Dutch month-ahead, a benchmark used in pricing LNG deliveries, was 0.5 euro down to 10.78 euros per megawatt hours.

* Benchmark Dec-19 EU carbon contract fell 0.1 euro to 28.37 euros a tonne. (Reporting By Sabina Zawadzki, editing by Deepa Babington)