* Day-ahead gas price rose by 0.80 pence to 27.05 pence per therm by 0900 GMT

* Within-day gas price fell by 0.55 pence to 26.25 p/therm

* UK gas system was 10.3 million cubic metres (mcm)oversupplied, with demand forecast at 124.2 mcm and supply at 134.5 mcm per day, National Grid data showed

* The oversupply drove the drop in the within-day price

* However, a new wave of maintenance work on Norwegian production starting next week helped lift other contracts

* A one-day outage at the Troll field will take place on Aug. 18 before a full shutdown of Troll and the Kollsnes processing plant starting from Aug. 24

* Moreover, two new planned maintenances are scheduled at Troll for Aug. 21-24, Gassco data showed

* "Troll and Kollnes maintenance is supporting the bulls as is carbon," a market source said

* There is also yearly maintenance at Norwegian fields which feed the UK's Entry SEGAL Pipeline System

* Liquefied natural gas (LNG) send-out remain low, at around 8 mcm/day, with one tanker from Qatar expected to deliver partial volumes to South Hook on Aug. 26

* Flows from Britain to Belgium via the Interconnector pipeline are expected to rise by 6 mcm on Friday to 21 mcm

* Wind generation is expected to be strong on Friday, at 11.1 gigawatts (GW) out of 12.1 GW capacity, according to Elexon

* Strong wind generation tends to reduce gas for power demand

* The British September contract was untraded

* Day-ahead gas price at the Dutch TTF hub edged up by 0.08 euro to 9.58 euros per megawatt hour (MWh)

* The Dutch month-ahead gas contract, a benchmark for LNG prices as well as European gas, was up by 0.08 euro to 11.18 euros per MWh

* The benchmark Dec-19 EU carbon contract rose 0.23 euro to 26.21 euros per tonne