Oil output is to rise by 1m barrels per day after Opec reached a deal today.
Shares in London-listed oil companies including Shell and BP rose on the news.
The group of 14 oil-producing countries reached an agreement after meetings in Vienna today, according to reports.
Meetings are set to continue into Saturday, when Opec meets with non-Opec allies.
The actual gain in output is likely to be smaller than 1m barrels per day, as some countries will not produce enough to meet the quota, while others will not be allowed to cover the shortfall.
Analysts suggest the gain be closer to around 600,000 barrels a day.
Saudi Energy Minister Khalid al-Falih said that an "immediate flood" of oil coming back into the market should not be expected.
Shares in BP were up 2.6 per cent this afternoon, Royal Dutch Shell's A shares and B shares made similar gains.
Read more: Opec’s next move