The main reasons are the lack of strict quarantine measures to counter the spread of COVID-19 in 2021.
Saudi Aramco said it would lower prices for all grades of crude for buyers from Asia and the Mediterranean in October.
OPEC+ kept its plan to increase oil production by 400 thousand barrels per day per month.
The decline lasted six straight sessions, the longest such period since February 2020.
Oil prices are falling on signals that a new strain of the Delta coronavirus has begun to negatively affect the Chinese economy.
Oil is slightly cheaper on Monday after a significant rise in quotations on Friday.
A corresponding bill has been registered in the Verkhovna Rada.
The price of Brent is approaching $70 a barrel, the price of WTI on Monday increased to a maximum in more than two years.
OPEC+ countries have retained the decision to gradually increase production in May-July.
Investors continue to monitor the epidemiological situation in Asia and are also waiting for the OPEC+ meeting.
Since the beginning of this week, Brent has decreased by 1.4%, WTI – 1.9%.
Oil quotations decline on Wednesday amid a new rise in the incidence of COVID-19 in Asia.