UPDATE 6-Oil below $108, US fiscal concerns weigh

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* Boehner offers to accept tax hike for wealthiest Americans

* Iran says oil revenue down by half (Updates prices)

LONDON, Dec 17 (Reuters) - Oil held around $108 a barrel on Monday as investors' concerns over the progress of U.S. budget deficit reduction talks countered support from signs of a brighter economic outlook in China.

The first real movement in U.S. "fiscal cliff" budget deficit talks began on Sunday, when Republican House Speaker John Boehner edged closer to President Barack Obama's key demands on taxation. Wall Street made early gains on Monday, but European stocks eased lower.

"The U.S. economy is on a good track, but we need the resolution of the fiscal cliff," said Andrey Kryuchenkov, analyst at VTB Capital.

">* Boehner offers to accept tax hike for wealthiest Americans* Iran says oil revenue down by half (Updates prices)LONDON, Dec 17 (Reuters) - Oil held around $108 a barrel on Monday as investors' concerns over the progress of U.S""Until then, from the point of view of investors, let's wait and see when we have a definite solution."

Brent crude for February was down 8 cents at $108.10 a barrel by 1459 GMT, having earlier risen as high as $108.50. U.S. crude for January was up 66 cents to $87.39.

In refinery news, Motiva Enterprises has again suspended the restart of its newly built 325,000 barrel-per-day crude unit at the Port Arthur, Texas, refinery after a small fire earlier on Monday, sources familiar with refinery operations said.

The sources said the unit was not being shut down, as it had been last week after an unexpected glitch, but that the process of gradually increasing production rates had been paused.

Oil had gained on Friday after surveys showed China's manufacturing sector grew in early December and that U.S. factories were having their best month since April.

"Brent has been having some short-term support at $108. Today it's broken below $108, but it certainly hasn't collapsed as a result," said Christopher Bellew, a senior oil broker at Jefferies Bache in London.

Brent hit a 2012 high of $128 in March and is on course to end the year little changed in percentage terms as economic worries have countered price-supporting supply disruptions in the Middle East and other regions such as the North Sea.

At present, forecasters such as the International Energy Agency expect sluggish growth in global oil demand in 2013.

On investors' horizons next year will be the continuing dispute between Iran and six world powers over Tehran's nuclear programme and any further impact on Iran's crude oil exports as a result of Western sanctions.

Iran's oil revenues have been cut in half this year from a year ago, a newspaper quoted Iran's economic minister as saying, an acknowledgment of how deeply sanctions are cutting into Tehran's chief source of funds.

Concern also persists over wider Middle East supply disruptions.

Iran plans to hold military drills in the Strait of Hormuz by next March, Iranian media quoted a commander from the Islamic Revolutionary Guards Corps (IRGC) as saying.

Iranian officials have said Iran could block the strait through which 40 percent of the world's seaborne oil exports pass, if it comes under military attack over its nuclear work, which Tehran says is for peaceful energy purposes. (Additional reporting by Florence Tan; Editing by Alison Birrane and Jane Baird)

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