UPDATE 5-Oil falls towards $108 on potential Libyan ports restart
* Libya aims to restart 3 eastern oil ports on Sunday
* Upbeat U.S. data raises prospect of Fed stimulus wind-down
* Pipelines set to drain Cushing glut
* Iran says new US measures violate spirit of nuclear deal
(Updates prices, paragraphs 5 and 12, bullets, adds quote, Iran story)
LONDON, Dec 13 (Reuters) - Brent crude oil fell towards $108 a barrel on Friday on prospects for ports in eastern Libya to resume exports and a possible scaling back of the U.S. Federal Reserve's massive stimulus programme.
Libya's government expects eastern tribes to reopen three oil ports this weekend, which could increase output at the OPEC producer from the current 250,000 barrels per day (bpd).
But there are doubts as to whether Libya can raise its output to pre-protest levels of more than 1 million bpd as internal conflicts continue to threaten its oil industry.
"I don't think anything is set in stone yet in terms of a definite restart, but market expectations are that the Libyan ports are going to restart," said Amrita Sen, chief analyst at consultants Energy Aspects.
January Brent was down 30 cents at $108.37 a barrel by 1233 GMT, following a fall of more than $1 on Thursday. U.S. crude futures for January were down 50 cents at $97, after rising around $6 in the past two weeks.
Upbeat economic data from the United States on Thursday heightened speculation that the Fed may start trimming its monthly bond purchases as soon as next week.
The move could strengthen the dollar and weigh on demand for dollar-denominated commodities such as oil. But stronger U.S. economic growth could also lead to higher fuel demand in the world's largest oil consumer.
Brent was supported by supply concerns arising from bombings near the Suez Canal, a major transportation channel for global oil markets.
U.S. oil also was supported by expectations that new pipelines starting in the coming weeks and next year could help reduce U.S. stockpiles.
Brent has slipped by more than 2 percent so far this week, the steepest weekly loss in seven weeks, and its premium to U.S. crude futures closed at $11.17 on Thursday, down more than $5 since the start of the month.
"It should be a general trend now that crude stocks in the U.S. continue to decline, and so we see a further contraction of the spread," said Bjarne Schieldrop, chief commodity analyst at SEB Bank.
Traders kept an eye on diplomatic relations between major powers and Iran. A lifting of sanctions on the OPEC producer's oil exports would increase global supply.
Iran said on Friday that a new U.S. measure targeting companies and individuals for supporting its nuclear programme violated the spirit of a nuclear deal reached with major powers in Geneva last month.
The European Union said that Iran and six world powers needed more time to work out complex technical steps on implementing last month's deal for Tehran to curb its nuclear programme.
(Additional reporting by Florence Tan in Singapore; Editing by Christopher Johnson and Jane Baird)