Saudi Arabia’s state-owned oil company, Saudi Aramco, cut oil cargo prices to Asia in October more than expected.
The company also lowered U.S. shipping prices for the first time in six months.
The rebates are seen as a sign that the company expects demand for oil to recover slowly.
Imports to China fell in August for the second month in a row.
Analysts also expect China to buy significantly less oil in September and October than in May and June.
At that time, independent oil refiners bought large quantities and their purchase quotas have now been used up.
Paul Horsnell, director of raw materials research at British Bank Standard Chartered, told news agency Bloomberg that it was time for prices to start falling.
Horsnell said the recovery in demand has been slightly weaker in recent months than estimated in the spring.
In London, the price of North Sea Brent-quality November deliveries had fallen 1.7 percent to $ 41.94 a barrel in the afternoon.
In New York, the price of WTI-quality October deliveries had fallen 1.9 percent to $ 39.02 a barrel.
The price of WTI-quality futures fell 7.5 percent last week.