OPEC kingpin Saudi Arabia and key oil ally Russia on Friday finalized their new production quotas, according to a source involved in the talks, agreeing to deeper cuts to bolster the market ahead of winter.

Under the deal, Saudi Arabia agreed to hold its crude production to 10.151 million b/d, down from its current quota of 10.311 million b/d, the source said.

Russia’s quota would be 11.121 million b/d, down from 11.191 million b/d.

The deal, which is yet to be made official, is part of a proposal to add 496,000 b/d in output curbs to the OPEC+ coalition’s existing 1.2 million b/d cut accord. OPEC would cut an additional 365,000 b/d under the plan, while the non-OPEC partners would cut an additional 131,000 b/d, the source said.

Iran, Libya and Venezuela remain exempt from the cuts, while Angola was allowed to maintain its current quota without any deeper cut.

The coalition would meet again March 5-6 in Vienna to review the cuts and decide whether to extend them beyond March, delegates said.

A Saudi-Russian co-chaired monitoring committee will meet March 4 to assess market conditions and provide recommendations to the wider 24-country OPEC+ coalition.