OPEC will supply a diminishing amount of oil in the next five years as output of U.S. shale and other rival sources expands, the exporter group said, despite a growing appetite for energy fed by global economic expansion.

OPEC's production of crude oil and other liquids is expected to decline to 32.8 million barrels per day (bpd) by 2024, the group said in its 2019 World Oil Outlook published on Tuesday. That compares with 35 million bpd in 2019.

"Non-OPEC supply prospects have been revised up sharply, as U.S. tight oil, in particular, has again outperformed expectations," OPEC Secretary-General Mohammad Barkindo wrote in the foreword of the report, using another term for shale.

Vienna-based OPEC expects supply of U.S. tight oil to reach 16.9 million bpd in 2024 from 12.0 million bpd in 2019, although the expansion will slow and peak at 17.4 million bpd in 2029.

The organisation, which pumps almost a third of global oil supply, now sees oil consumption in 2023 reaching 103.9 million bpd, down from 104.5 million bpd in last year's report. Longer-term, oil demand is expected to increase by 12 million bpd to reach 110.6 million bpd by 2040, also lower than last year's forecast.