Crude prices fell on Friday amid concern about the persistent oversupply of oil and skepticism that major oil producers will be able to coordinate the production cut they agreed to last month.

U.S. crude for November delivery settled down 9 cents, or 0.18 per cent, at $50.35 a barrel on the New York Mercantile Exchange. Brent crude, the global oil benchmark, fell 8 cents, or 0.15 per cent, to $51.95, on the ICE Futures Exchange in London, reported the Wall Street Journal.

Despite Friday’s move lower, oil prices ended the week up 1.08 per cent - the fourth consecutive week of gains and the longest weekly winning streak since April.

But analysts and traders said oil wasn’t able to maintain the momentum that pushed it to a one year high earlier this week.

“We need some other kind of bullish factor to get a sustained move from here,” said Tariq Zahir, managing member of Tyche Capital Advisors. “The market is telling me we have more than enough inventories out there.”

Four additional oil rigs went to work in the U.S. last week - the seventh consecutive weekly increase in the rig count, according to oil-field services firm Baker Hughes.