London Brent crude for November delivery was down 4 cents at $47.22 a barrel by 2018 EST, after settling down 37 cents on Tuesday, according to Reuters.
NYMEX crude for October delivery was down 8 cents at $44.75, after settling up 39 cents on Tuesday.
Oil prices hit a one-week high on Monday after Russia and Saudi Arabia agreed to cooperate on stabilising the oil market, but they have since fallen due to the mounting uncertainty over a deal.
The Organization of the Petroleum Exporting Countries and non-OPEC producers such as Russia will hold informal talks in Algeria on September 26-28, but many in the market are sceptical a deal will happen, Reuters wrote.
Saudi Arabia's Foreign Minister Adel al-Jubeir said on Tuesday it would go along with a freeze in oil output if other producers agreed one but cautioned that Iran, which is aiming to raise output to pre-sanction levels, could foil any attempt to limit output.
Iran, however, signalled on Tuesday it was prepared to work with Saudi Arabia and Russia to prop up oil prices as it began to bargain with OPEC on possible exemptions from output limits, according to the report.