* Libya aims to restart 3 eastern oil ports on Sunday
* Upbeat U.S. data raises prospect of Fed stimulus wind-down
* Pipelines set to help draw down U.S. stockpiles
* Iran, Russia say US steps violate spirit of nuclear deal
(Updates quotes, prices, paragraphs 5-7, 11 and 13)
LONDON, Dec 13 (Reuters) - Brent crude fell towards $108 a barrel on Friday on prospects for oil ports in eastern Libya to resume exports and a possible scaling back of the U.S. Federal Reserve's stimulus programme.
Libya's government expects eastern tribes to reopen three oil ports this weekend, which could increase the OPEC producer's shipments from the current 110,000 barrels per day.
"There's a general consensus that some sort of additional oil will emerge from Libya," said Gareth Lewis-Davies, senior energy strategist at BNP Paribas. "But there's uncertainty on how much and particularly how long it will last."
There are doubts as to whether Libya can raise its output significantly as internal conflicts threaten its oil industry.
January Brent was down 35 cents at $108.32 a barrel by 1425 GMT, following a fall of more than $1 on Thursday. Brent has slipped 3 percent so far this week, the steepest weekly loss since the end of September.
U.S. crude futures for January were down 90 cents at $96.60 a barrel, after rising around $6 in the past two weeks.
The premium between Brent crude and U.S. oil - also known as West Texas Intermediate (WTI) - was $11.72, down more than $5 since the start of the month.
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 speculation strengthened the dollar and weighed on demand for dollar-denominated commodities such as oil.
"In the last 24 hours or so, we've seen an improvement in the strength of the dollar and WTI is off as a consequence," BNP Paribas' Lewis-Davies said.
Brent was supported by supply concerns arising from bombings near the Suez Canal, a major transportation channel for global oil markets.
U.S. oil gained support from expectations that new pipelines starting in the coming weeks and next year could help reduce U.S. stockpiles.
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.
Russia echoed Iran on Friday, saying 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 last month.
The European Union said Iran and six world powers needed more time to work out complex technical steps on implementing the deal for Tehran to curb its nuclear programme.
(Additional reporting by Florence Tan in Singapore; Editing by Christopher Johnson, Jane Baird and Dale Hudson)