UK GAS-Prices mostly rise on higher demand forecasts

LONDON, July 2 (Reuters) - British wholesale prompt gas prices mostly rose on Monday due to higher gas-for power demand and strong exports to Belgium which could increase further this week.

* Day-ahead gas rose by 0.55 pence per therm to 54.25 p/therm at 0924 GMT amid forecasts of higher gas-for-power demand due to declining wind output

* Within-day gas was 1.00 pence higher at 54.50 p/therm

* The August contract was up 0.90 pence at 56.50 p/therm

* Residential and commercial demand should also rise by 2 million cubic metres (mcm) per day to 56 mcm/day

* Weather forecasts monitored by Thomson Reuters (Dusseldorf: TOC.DU - news) analysts showed higher average temperatures for Monday by up to 1.7 degrees Celsius to 20.4 degrees

* The current spell of above-average temperatures is expected to continue throughout the week at around 20 degrees C, according to Thomson Reuters weather data

* The system was oversupplied by 11.3 mcm with demand at 184.4 mcm, slightly above seasonal averages, and supply seen at 195.7 mcm/day, according to National Grid (LSE: NG.L - news) data

* Norwegian exports to Britain jumped by 26 mcm/day to 77 mcm/day, but a rising share of that could be diverted to mainland Europe where prices are fetching a premium, cutting into UK supply availability

* UK Continental Shelf gas supplies steadied at 105 mcm/day.

* Gas exports out of Britain to Belgium through the InterconnectorUK pipeline are expected to remain robust at 55 mcm/day this week, another factor helping to lift gas contracts

* Day-ahead gas at the Dutch TTF hub rose by 0.57 euro to 22.15 euros per megawatt-hour

* The benchmark Dec (Shanghai: 600875.SS - news) -18 EU carbon contract was flat at 15.08 euros a tonne. (Reporting by Oleg Vukmanovic; Editing by Nina Chestney)