Oil prices fell more than 1% on Wednesday, extending this week's losses to hit fresh four-month lows on signs that more oil tankers are set to move out of the Strait of Hormuz.
Brent crude futures were down $1.37, or 1.8%, at $75.71 a barrel by 0805 GMT. US West Texas Intermediate slipped by $1.08, or 1.5%, to $72.13.
Brent touched a low of $75.60, its weakest level since February 27, the day before the initial US-Israeli strikes on Iran. WTI fell as low as $72.03, the weakest since March 3.
"While there are early encouraging signs of increased tanker activity, the market is pricing in the broader scenario of Iranian oil re-entering the global market and the Strait of Hormuz normalising," said Tim Waterer, chief market analyst at KCM Trade.
"If sanctions are eased, Iranian production and exports could ramp up relatively quickly given the substantial amount stored on tankers — we are likely talking weeks rather than months," Waterer added, Reuters reported.
Prices have also come under pressure this week from the 60-day sanctions waiver Washington granted Tehran after initial peace talks, allowing Iran to sell oil, and from an easing of hostilities in Lebanon, with prices approaching pre-war levels.
Ship-tracking data showed that three stranded supertankers passed through the strait on Tuesday. The UN shipping agency said an evacuation plan is under way to enable hundreds of stranded ships to sail through the strait after the US-Iran ceasefire deal.
On Tuesday, Oman and Iran agreed to press on with discussions about managing navigation in the strait. US Secretary of State Marco Rubio said that any attempt by Iran to levy transit fees would violate international law.
Uncertainty remains over the durability of the accord, however. US President Donald Trump said on Tuesday that Iran had agreed to nuclear inspections into "infinity", though Tehran said it had made no such concession.
"Markets are currently assigning too much confidence to a favorable outcome without fully discounting the risks associated with unresolved nuclear issues and inspection disputes," said Mark Malek, CIO at Siebert Financial.
Investors are also watching how quickly Middle Eastern producers can restore exports and whether more ships will enter the region.
Meanwhile, US crude stocks fell by 765,000 barrels in the week to June 19, market sources said, citing data from the American Petroleum Institute.
Nine analysts polled by Reuters estimated, on average, that crude inventories fell by about 4.5 million barrels in the past week.
