Benchmark Brent oil edged up on Dec. 7 after indications Russia would contribute a bigger output cut than previously suggested to an OPEC and non-OPEC deal, although prospects for an overall agreement still hung in the balance.

Brent had nudged up 40 cents to $60.46 a barrel by 1133 GMT after falling below $60 in early trade. U.S. West Texas Intermediate (WTI) crude futures was steady, up a modest 3 cents at $51.52 per barrel.

Crude fell almost 3% on Dec. 6 after the Organization of the Petroleum Exporting Countries ended Thursday's meeting in Vienna with only a tentative deal to tackle weak oil prices. Talks with other producers would be held on Friday.

Oil prices have plunged 30% since October, as supply has surges as the global demand outlook weakens.

Iran appeared to be the main obstacle to an OPEC deal on output cuts on Friday. OPEC sources said the group's de facto leader Saudi Arabia was opposed to exemptions in the deal demanded by Iran, which is under U.S. sanctions.

Saudi Energy Minister Khalid al-Falih said he was not confident a deal could be reached.

OPEC is seeking to win support from non-OPEC Russia for supply cuts. Russian Energy Minister Alexander Novak returned to Vienna on Friday after discussing the issue with President Vladimir Putin.

A Russian Energy Ministry source said Moscow was ready to contribute a cut of around 200,000 bpd, which is more than the 150,000 bpd sources previously said it would contribute.

Analysts said a big cut would be needed to reverse recent price falls and Russia's contribution would be vital.

"Reversing the overwhelmingly bearish price sentiment will likely require a credible and cohesive message from the OPEC meeting," U.S. investment bank Jefferies said, adding that 1 MMbbl/d would not be enough.

Oil output from the world's biggest producers - OPEC, Russia and the United States—has increased by 3.3 MMbbl/d since the end of 2017 to 56.38 MMbbl/d, meeting almost 60% of global consumption.

The surge is mainly due to soaring U.S. oil production, which has jumped by 2.5 MMbbl/d since early 2016 to a record 11.7 MMbbl/d, making the U.S. the world's biggest producer.

The U.S., which is not party to any output deal, last week exported more crude oil and fuel than it imported for the first time in records going back to 1973, data showed.