09:04 AM EDT, 05/14/2025 (MT Newswires) -- Oil prices weakened early on Wednesday following a report showing U.S. inventories unexpectedly rose last week, heightening concerns the market is becoming oversupplied, even as OPEC issued another optimistic outlook for demand growth this year.

West Texas Intermediate crude oil for June delivery was last seen down US$0.72 to US$62.95 per barrel, while July Brent oil was down US$0.70 to US$65.93.

In its weekly survey, the American Petroleum Institute reported U.S. oil inventories rose by 4.29-million barrels last week, while the consensus estimate from analysts polled by Oilprice.com expected a drop of 2.4-million barrels. The Energy Information Administration will release official inventory data later on Wednesday morning.

The rise in stocks comes as OPEC+ readies to add another 411,000 barrel per day tranche of supply to the market as it unwinds 2.2-million barrels per day of voluntary production cuts. The new supply is likely to check prices as Saudi Arabia looks to regain market share and respond to a U.S. call for lower prices, even as U.S. President Donald Trump began the first presidential trip of his current term with a visit to Riyadh on Tuesday.

"While OPEC officials maintain that the US played no role in the decision to accelerate the phase -in of the voluntary barrels, the oil price environment has provided a beneficial backdrop to the Presidential visit from the Washington standpoint, Helima Croft, Head of Global Commodity Strategy and MENA Research at RBC Capital Markets, said in a note.

OPEC released its May Monthly Oil Market Report on Wednesday, sticking with its forecast for 2025 demand growth of 1.3-million barrels per day, higher last week's estimate from the Energy Information Administration for demand growth of one-million bpd this year. The International Energy Agency will release its monthly outlook on Thursday.

The cartel also lowered its estimate from production growth for countries outside of OPEC+ by 100,000 bpd to 0.8-million bpd.