* Libya's El Feel oilfield shut again by protesters
* 12 dead in clashes in Libya's Benghazi
* Russia offers Ukraine natgas discount
* Washington warns Russia of further sanctions over Ukraine
* U.S. consumer sentiment falls in May
(Adds CFTC data)
NEW YORK, May 16 (Reuters) - Brent crude oil rose on Friday to end nearly 2 percent higher on the week, boosted by concerns over output in Libya, where recently opened fields were closed again and clashes erupted in the east.
Protesters again shut Libya's El Feel oilfield and the El Sharara field remained closed, an official at the National Oil Corporation said on Friday. Output edged down to about 200,000 barrels per day (bpd), far less than the 1.4 million bpd pumped last year.
In the east, Libyan irregular forces clashed with Islamist militias in Benghazi, killing at least 12.
"We have to take Libyan reports that these oilfields are back up with a grain of salt because it's still very uncertain there," said Joseph Posillico, senior vice president of energy derivatives at Jefferies Bache in New York. "Some of that is supporting Brent."
Brent crude settled 66 cents higher at $109.75 a barrel, ending the week 1.8 percent higher.
U.S. crude settled 52 cents higher, or 0.51 percent, at $102.02 a barrel, or 2 percent higher than last week.
The U.S. benchmark spent the entire week above the 50-day moving average of $100.99 but found resistance at $102.65, trading in a new range that is closely linked to gasoline prices, analysts said.
"What we have is a stall at $102.60; the market stopped there, it didn't lower much," said Walter Zimmermann, chief technical analyst at United-ICAP. "The fate of U.S. crude to the upside is in the hands of gasoline. When we look at RBOB, we see a market that is much closer to being a sell than to be a buy."
U.S. gasoline rose nearly 3 percent over last week, and settled about a penny higher at $2.9735 a gallon.
Money managers raised their net long U.S. crude futures and options positions in the week to May 13, the U.S. Commodity Futures Trading Commission said. In the week to May 6, the speculator group cut net long positions.
The conflict in Ukraine remained a background support as U.S. Secretary of State John Kerry warned Russia it faced broader sanctions if it interferes in Ukraine's presidential elections on May 25.
Meanwhile, Russia offered Ukraine a discount on its June natural gas supply if it paid $2.2 billion of the $3.5 billion debt Moscow says Kiev owes as of April 1.
In the United States, economic data offered contrasting pictures for growth in the world's largest oil consumer.
A gauge of U.S. consumer sentiment fell in May as a gloomy view on income growth clouded an otherwise positive economic outlook, a preliminary reading of the Thomson Reuters/University of Michigan survey showed.
U.S. housing starts jumped in April and building permits hit their highest in nearly six years.
Investors kept an eye on talks due to end Friday over Tehran's nuclear program. A senior U.S. official said Iran and six world powers were making little progress, fanning doubt about prospects for a breakthrough by a self-imposed July deadline.
Iran's oil exports averaged 1.11 million bpd in April, the second monthly drop in a row, the Paris-based International Energy Agency said, and close to the 1 million bpd allowed under November's pact.
(Additional reporting by Peg Mackey in New York and Keith Wallis in Singapore; Editing by William Hardy, David Evans, G Crosse, David Gregorio and James Dalgleish)