The U.S. Energy Information Administration did not publish its weekly petroleum status report at 10:30 a.m. ET (1530 GMT) as expected.
The agency faced technical difficulties publishing the report on time, EIA officials said.
The EIA said it was looking into the issue but did not provide a timeline for the data release.
(Reporting by Nicole Jao in New York and Arathy Somasekhar in Houston Editing by Rod Nickel)