A survey conducted by Reuters on Tuesday indicated that the Organisation of Petroleum Exporting Countries' (OPEC's) oil production increased in May due to higher exports from Nigeria and Iraq.
It said the development offset the impact of the ongoing voluntary supply cuts by some members within the wider OPEC+ alliance.
The survey, based on shipping data and industry sources, revealed that OPEC pumped 26.63 million barrels per day last month, up 145,000 barrels per day from April.
Despite commitments from Iraq and Kazakhstan to make further cutbacks to compensate for earlier over-production, Iraq, OPEC's second-largest producer, increased its output.
OPEC+ members, including Russia and other allies, implemented new cuts in January to counter economic weakness and increased supply outside the group, with those cuts being extended until June and then further into the third quarter.
In May, Iraq and Nigeria raised their outputs by 50,000 barrels per day each, while Algeria reduced its output due to oilfield maintenance.
The survey also found that OPEC exceeded the implied target for the nine members covered by supply cut agreements by about 250,000 barrels per day, with Iraq accounting for the majority of the excess. Additionally, Iran and Venezuela, not required to cut output, slightly increased their production.
Despite US sanctions, Iran's output is near a five-year high reached in November after posting one of OPEC's biggest output increases in 2023.