* Within-day gas down 0.25 percent at 34.25 p/therm
* UK gas storage sites 47 pct full
LONDON, July 5 (Reuters) - British wholesale gas prices declined on Tuesday morning on more injections into medium range storage facilities and continued exports to Europe.
Gas for instant delivery was 0.25 pence lower at 34.25 pence per therm at 0743 GMT from the previous settlement, while the day-ahead contract was down by 0.15 pence at 34.30 pence per therm.
Flows, demand and liquefied natural gas supply are mostly in line with the previous trading session, traders said.
The UK gas system is forecast to be roughly balanced on Tuesday, National Grid (LSE: NG.L - news) data shows, with flows from the UK Continental Shelf and through Langeled from Norway roughly unchanged from Monday.
"As Rough is out of action until at least August, there is a need to put gas into medium-range storage ahead of winter," a UK gas trader said.
UK gas storage facilities are currently around 47 percent full, according to Gas Infrastructure Europe data.
Rough is Britain's only long-range storage site. Gas is usually injected there in the summer and taken out in the winter. The site has been shut down until at least Aug. 3 due to well testing, leaving it likely the UK will go into next winter with record low storage inventories.
Other storage sites in Britain are medium range which means they have shorter injection and withdrawal times and can react more quickly to demand.
Exports to Europe through the InterconnectorUK (IUK) pipeline are at around 40 mcm/d, in line with Monday's flows.
"We expect a level of around 40-45 mcm/d of IUK exports over the rest of our forecasting period. High IUK exports are correlated with the fact that the UK system is stripped out of Rough demand until August 3," said Dimitrios Saratzis, analyst at Thomson Reuters (Dusseldorf: TOC.DU - news) .
In the Dutch gas market, the day-ahead gas contract at the TTF hub was down 0.20 euro at 14.20 euros per megawatt-hour.
In Europe's carbon market, the front-year EU allowance price fell by 0.14 euro to 4.83 euros per tonne. (Reporting by Nina Chestney)