LONDON, Sept 4 (Reuters) - OPEC+ is likely to keep oil output quotas unchanged for October at a meeting on Monday, six OPEC+ sources said, though some sources would not rule out a small production cut to bolster prices that have slid on fears of an economic slowdown.

The Organization of the Petroleum Exporting Countries (OPEC) and allies including Russia, known collectively as OPEC+, are expected to roll over existing policies, six OPEC+ sources said on Sunday and Monday.

However, three of the sources said the producer group could also discuss a small cut of 100,000 barrels per day (bpd).

Monday's OPEC+ meeting is set against a complex backdrop including a potential supply boost from Iranian crude returning to the market if Tehran is able to revive its 2015 nuclear deal with global powers.

Russia, meanwhile, has said it will stop supplying oil to countries that support the idea of capping the price of Russian energy supplies over its military conflict in Ukraine.

Russia's gas deliveries in Europe, meanwhile, have been cut further, which is likely to spark more price spikes.

 

Brent crude oil has dropped to about $95 a barrel from $120 in June on fears of an economic slowdown and recession in the West.

Iran is expected to add 1 million bpd to supply, or 1% of global demand, if sanctions are eased, though the prospects for a nuclear deal looked less clear on Friday.

Top OPEC producer Saudi Arabia last month flagged the possibility of output cuts to address what it sees as exaggerated oil price declines.

"OPEC+ is wary of protracted price volatility generated by weak macro sentiment, thin liquidity and renewed China lockdowns, as well as uncertainty over a potential U.S.–Iran deal and efforts to create a Russian oil price cap," said Matthew Holland at Energy Aspects.

Signals from the physical market, however, suggest that supply remains tight and many OPEC states are producing below targets while fresh Western sanctions are threatening Russian exports.

"An output cut won't make them any friends at a time when the world is facing a cost-of-living crisis," ... The more sensible option may be to hold this month and revisit in the future when there's more clarity," said Oanda analyst Craig Erlam. (Additional reporting by Rowena Edwards and Olesya Astakhova Writing by Dmitry Zhdannikov Editing by David Goodman)