LONDON — Oil resumed its decline as industry data showed U.S. crude stockpiles extended gains and as the IEA predicted new output from OPEC’s rivals will exceed demand growth next year.

Futures lost as much as 1.6% in New York after rising 1.8% in the previous three sessions. The American Petroleum Institute signaled U.S. inventories probably climbed a second week, ahead of data from the EIA forecast to show a decline. New supplies from OPEC’s competitors will be more than enough to meet growth in demand next year, the IEA said in a report Wednesday.

Oil is extending its slump below $50/bbl amid speculation rising U.S. supplies will counter production curbs by OPEC and allies including Russia. Output at major American shale fields will reach a record in July, according to the EIA.

“The market tightening intended by OPEC has thus failed to materialize,” Carsten Fritsch, an analyst at Commerzbank AG in Frankfurt, said in a report. “OPEC will therefore have to cut production further next year to ensure that the oil market is not oversupplied.”

WTI for July delivery slid as much as $0.74 to $45.72/bbl on the NYME, but bounced back to $46.13. Total volume traded was 10% above the 100-day average. Prices gained $0.38 to $46.46 on Tuesday.

Brent for August settlement lost as much as $0.70, or 1.4%, to $48.02/bbl on the London-based ICE Futures Europe exchange, after climbing 0.9% on Tuesday. Brent traded at a premium of $2.13 to August WTI.

U.S. crude inventories added 2.75 MMbbl last week, while gasoline stockpiles increased by 1.79 MMbbl, the API said Tuesday, according to people familiar with the data. The EIA is forecast to report crude stockpiles slid 2.45 MMbbl and motor-fuel inventories dropped by 1.15 MMbbl, according to the median estimate in a Bloomberg survey.

The U.S., Brazil, Canada and other producers outside OPEC will increase output next year by the most in four years, the IEA said in its first forecast for 2018. As a result, the need for crude from OPEC won’t be high enough for the group to reverse cuts it’s currently making to drain a global glut.

Oil Market News

OPEC production rose more than 336,000 bpd in May from a month earlier to 32.14 MMbpd, according to a monthly report from the group on Tuesday. China’s crude output in May fell 1.8% from the previous month to average 3.84 MMbpd, the lowest since October, according to Bloomberg calculations based on data Wednesday from the National Bureau of Statistics. Oil stockpile draws will accelerate in the second half of 2017, according to BP Plc Chief Economist Spencer Dale.