To update prices and add details

CALGARY, ALBERTA, June 19 (Reuters) - Brent crude rose slightly on Friday but was on track for a weekly loss of about 8 percent after Israel and Hezbollah agreed to a ceasefire in Lebanon, while Iran set conditions for passage through the Strait of Hormuz.

Brent crude futures rose 66 cents, or 0.53 percent, to $80.38 a barrel by 1:30 p.m. EST, while U.S. West Texas Intermediate crude futures climbed 94 cents, or 1.23 percent, to $77.54 a barrel.

Trading volumes were weak due to a federal holiday in the United States.

Gulf oil producers are preparing to increase their exports after the ceasefire agreement between Israel and Hezbollah came into effect at 4 p.m. local time (1300 GMT).

Despite the increased traffic through the strait, Iran has indicated it is tightening controls on maritime shipping. State television reported that ships must coordinate their passage with the Islamic Revolutionary Guard Corps Navy.

In an alert distributed to the maritime transport sector in the past 24 hours and seen by Reuters, the Persian Gulf Strait Authority, an Iranian body established to manage the Strait of Hormuz, said that "no vessel will be allowed to cross the Strait of Hormuz without a valid passage permit issued by the Authority."

Rory Johnston, founder of the Commodity Context newsletter, said concerns about Iranian conditions for using the Strait of Hormuz contributed to pushing oil prices higher today.

Despite gains on Friday, Brent crude fell by about eight percent compared to the previous week, reflecting a significant decrease in supply concerns following the agreement between the United States and Iran to end the war.

Iran's Foreign Ministry announced on Friday that a meeting scheduled between Iranian and American officials in Switzerland had been postponed, noting that arrangements were underway for talks to take place in the coming days.

The ministry explained that the meeting was no longer urgent after a memorandum of understanding on ending the war was signed electronically between the two sides.

Analysts expect the agreement to release more than 85 million barrels of oil currently trapped in the Gulf region of the Middle East into global markets. The agreement also includes the lifting of US sanctions on Iranian oil, which will further increase supplies.

Before the war, roughly 20 percent of the world's oil and liquefied natural gas supplies passed through the strait, but a recovery in flows and production following the US-Iran agreement could take several months.

Iraqi Oil Minister Bassem Mohammed said that the oil fields are ready to resume production and that the return to normal "will be gradual until previous production rates are reached."

On the demand side, the Organization of the Petroleum Exporting Countries (OPEC) said in its World Oil Outlook 2026 that global demand will rise to 113.3 million barrels per day in 2030 from 105.1 million in 2025.