UPDATE 1-UK forward gas up with oil on EU Iran ban

* Iran renews threat to close Strait of Hormuz

* Colder weather drives prompt contracts

* EDF Energy restarts Heysham 1-1 nuclear reactor (Updates throughout)

LONDON, Jan 23 (Reuters) - British summer 2012 gas prices rose to its highest in 10 days on Monday as crude oil lent support after EU foreign ministers agreed to ban Iranian imports.

The benchmark front-season contract rose to 53 pence per therm on Monday afternoon, the highest since Jan. 13 and up 0.70 pence on Friday's closing price, broker data showed.

The forward contract tracked gains above the 111-dollar mark in the Brent crude market, where the EU's move to place an oil embargo on Iran raised fears of supply disruptions.

The latter also reiterated threats to block the Strait of Hormuz, a key shipping route also for liquefied natural gas (LNG) from export leader Qatar.

"If real disruptions occurred (in the Strait of Hormuz), the initial reaction would be prices rising to all-time highs on the NBP," said a European gas trader at a utility.

Britain is particularly dependent on LNG supply from Qatar as all but one cargo of the super-cooled fuel which Britain imported between August and December 2011 came from the Middle Eastern producer.

Winter 2012 gas also rose, adding 0.60 pence to 65.80 pence.

Prompt gas prices also firmed on the back of colder weather forecasts, but the system was well supplied on Monday and demand remained below seasonal norms, National Grid data showed.

Monday gas consumption sank 8 percent below normal levels and Tuesday demand was pegged 9 percent lower than usually at this time of the year.

Tuesday gas traded at 54.00 pence, up 0.65 pence on the previous session, while within-day gas traded at 53.70 pence.

WEATHER

In its late-January to early-February forecast, the UK's Met Office said that temperatures will likely remain at average levels, with a risk of colder weather towards the end of the period.

POWER

In Britain's power market day-ahead baseload rose 30 pence to 42 pounds per megawatt hour, broadly in line with gas market sentiment.

The contract rose despite additional supply being made available to the system as EDF Energy reconnected its Heysham 1-1 nuclear reactor on Sunday. (Reporting by Karolin Schaps and Oleg Vukmanovic)