OPEC said on Wednesday its oil production jumped in June and forecast world demand for its crude will decline next year as rivals pump more, pointing to a market surplus in 2018 despite an OPEC-led output cut, Reuters reports.

Giving its first 2018 forecasts in a monthly report, the Organization of the Petroleum Exporting Countries said the world will need 32.20 million barrels per day (bpd) of crude from its members next year, down 60,000 bpd from this year.

OPEC said its oil output in June rose by 393,000 bpd to 32.611 million bpd, above the demand forecast, led by gains in Libya and Nigeria, two members exempt from the cut aimed at eliminating excess supply. OPEC officials nonetheless remain upbeat on the outlook.

Supply is rising outside the group as well. OPEC estimated supply from all non-OPEC producers next year will rise by 1.14 million bpd, a sizeable increase from growth of 800,000 bpd this year led by the United States. Should OPEC keep pumping at similar levels to June, the market could remain in surplus next year, the report indicates.