Saudi Arabia and Russia, both of whom have boosted their crude output in recent months, were responsible for a $15/b drop in the price of oil and "should cut at least 1 million b/d instantly", an OPEC delegate told S&P Global Platts.
The comments come as Saudi Arabia and Russia were reportedly discussing a production cut in 2019, Russian news agency Tass reported earlier Wednesday.
Saudi officials could not be reached for comment.
ICE Brent futures were trading at $73.03/b at 1307 GMT Wednesday, after hitting a four-year high October 3 at $86.29/b.
A six-country OPEC/non-OPEC Joint Ministerial Monitoring Committee co-chaired by Saudi Arabia and Russia meets Sunday in Abu Dhabi to assess market conditions. The next full OPEC meeting is December 6 in Vienna.
The coalition on June 23 agreed to raise production by a combined 1 million b/d from May levels by reducing overcompliance with production cuts, in order to offset expected losses by sanctions-hit Iran and Venezuela.
Saudi energy minister Khalid al-Falih said last month the kingdom was producing about 10.7 million b/d, near its record high and almost 700,000 b/d more than it was producing in May.
Russia, meanwhile, reported Friday that it hit an all-time high of 11.41 million b/d, up about 440,000 b/d from May.