Oil prices hit a six-week high on Thursday as oil rigs in the Gulf of Mexico were evacuated ahead of a storm, while an incident with a British tanker in the Middle East highlighted tensions in the region.
However, prices gave up most gains as OPEC forecast that world demand for its crude would decline next year as rivals pumped more, pointing to the return of a surplus despite an OPEC-led pact to restrain supplies.
Brent crude futures were up 2 cents at $67.03 a barrel by 1330 GMT. Earlier in the session, they hit their highest since May 30 at $67.65, after ending Wednesday up 4.4%.
U.S. West Texas Intermediate crude futures were up 9 cents at $60.52 a barrel, having touched their highest since May 23 at $60.94. They gained 4.5% in the previous session.
A day after Iran warned Britain would face “consequences” over the seizure of an Iranian oil tanker, three Iranian vessels tried to block the passage of a British ship run by BP through the Strait of Hormuz, the British government said. They withdrew after warnings from a British warship.