The combined supply cuts have helped to drive a 32 percent rally in crude prices this year to almost $72 a barrel, prompting U.S. President Donald Trump to call on OPEC to ease its market-supporting efforts.
Global oil demand is estimated to average 99.91 million bpd this year, compared with 98.70 million bpd in 2018, OPEC said.
After a production glut lead to prices dropping past year, OPEC members and allies including Russian Federation agreed in December to trim production.
OPEC also revised down non-OPEC oil supply growth in 2019 by 60,000 bpd "due to extended maintenance in Kazakhstan, Brazil and Canada".More news: One dead following tornado in Monroe County
The March figure is down from 30.56 million bpd in February, largely on a huge fall in production from Venezuela and Saudi Arabia.
In 2018 OPEC+ made a decision to increase output at its mid-year meeting, only to return to production cuts in 2019.
The report pointed to a slightly under-supplied market in 2019 if OPEC kept pumping at March's level.
Oil markets have been lifted by more than 30 percent this year by supply cuts led by the Organization of the Petroleum Exporting Countries and USA sanctions on oil exporters Iran and Venezuela, plus escalating conflict in OPEC member Libya. Saudi Arabia is set on maintaining the production cuts into the second half of 2019, while Russian Federation refuses to commit to an extension.More news: House committee chair extends deadline for Trump's tax returns
Oil prices fell yesterday, after rising to five-month highs earlier this week on the Organisation of Petroleum Exporting Countries (OPEC)-led production cuts and free-falling Venezuelan output. "It all depends on where prices are by the end of May and June".
Saudi Arabia's crude oil production slumped to the lowest in two years as the Kingdom slashed its production by more than promised to boost prices.
"Crude oil production has not been affected so far and if we can not reduce the Libyan risk to zero, we go into this weekend with a lower risk premium for Libya than a week ago", said Olivier Jakob at PetroMatrix in Zug, Switzerland.
"Russia has started talks about an oil production rise as it can hardly follow the OPEC+ deal", said another Russian energy source.More news: BTS Fans Left Hypnotised as K-Pop Boy Band Makes SNL Debut