* Libya's El Feel oilfield shut again by protesters
* Washington warns Russia of further sanctions over Ukraine
* U.S. concerned by lack of progress in Iran nuclear talks
LONDON, May 16 (Reuters) - Brent crude oil rose above $109 a barrel on Friday after a recovery in Libyan oil supply proved short-lived and as tension simmered over Ukraine.
Libya's El Feel oilfield has been shut again by protests and the OPEC producer's El Sharara field remains closed, bringing national oil output down to about 200,000 barrels per day (bpd) - far from the 1.4 million bpd pumped last year.
On Monday, the government said it was bringing western oilfields and pipelines back up after reaching a deal with protesters, and output had slowly clawed back to around 300,000 bpd.
Brent crude rose 41 cents to $109.50 a barrel by 1338 GMT. U.S. crude climbed 27 cents to $101.77.
U.S. Secretary of State John Kerry warned Russia it faced broader economic and industrial sanctions from the United States and Europe if it meddled in Ukraine's presidential elections on May 25.
"The situation with Ukraine is stopping sellers being too aggressive," said Ric Spooner, chief market analyst at CMC Markets.
Investors are also keeping 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 in arduous talks on ending their dispute over Tehran's nuclear program, fanning doubt about the prospects for a breakthrough by a self-imposed July deadline.
Iran's oil exports averaged 1.11 million barrels per day (bpd) in April, the second month in a row exports have fallen, the Paris-based International Energy Agency said. That is close to the 1 million bpd allowed under November's pact.
(Additional reporting by Keith Wallis; in Singapore; Editing by William Hardy and David Evans)