
Oil prices fell on Monday amid worries about an economic slowdown and the US-Chinatradewar, which have led to a cut in the outlook for global oil demand.
International benchmark Brent crude futures were at $58.16 a barrel by 0829 GMT, down 37 cents from their previoussettlement.
USWest Texas Intermediate (WTI) futures were at $53.89 per barrel, down 61 cents from their last close.
Both benchmarks fell last week, with Brent losing more than 5% and WTI falling about 2%.
Although the third quarter is fundamentally the strongest season for oil demand because of driving in summer holidays, thetradedisputebetween the United States andChinahas weakened demand and reduced crude prices.
USPresident Donald Trump said on Friday he was not ready to make a deal withChinaand even called a September round oftradetalks into question.
"The market is facing a buyers' strike," said Michael Tran, commodity strategist at RBC Capital Markets, noting the low level of investors' long positions betting on higher prices.
"Despite the laundry list of disruptions and additional barrels at risk, investor length is currently near a multi-year low."
Goldman Sachs Group Inc said on Sunday it no longer expects atradedeal between the world's two largest economies before the 2020 US presidential election.
The International Energy Agency (IEA) said on Friday mounting signs of an economic slowdown had caused global oil demand to grow at its slowest pace since the financial crisis of 2008.
OPEC members continue to cut production to drain global oil inventories, with the Saudis cutting more than their agreed quota, but analysts said more cuts were needed to support prices due to a fall in demand and non-OPEC supply growth next year.
"If OPEC cuts are merely extended through 2020, prices are going to fall further from current levels," Bernstein Energy said in a note on Monday.
"We believe that OPEC needs to cut by a further one million barrels per day in 2020 if they are to defend oil prices at $60 a barrel."
In a sign of lower production in the United States, the weekly USoil rig count, an early indicator of future output, fell for a sixth straight week as producers cut spending on new drilling and completions.
India's imports of crude oil have also stalled in recent months, a fall that tallies with weaker economic growth in the country.