LONDON: Oil prices extended gains yesterday as the market considered the impact of reduced Iranian exports and a fall in US stockpiles. Brent crude gained more than 50 cents a barrel at $77.64 by midday in London, taking its weekly gain to almost 10 percent. US light crude was 40 cents higher at about $69.91. “The oil market is once again tightening after a short period in late June and early July when it was likely oversupplied,” said Giovanni Staunovo, an analyst at UBS Group AG in Zurich. “Iranian oil export declines are already visible well in advance of US oil-related sanctions.” Most of Iran’s customers are already facing difficulties in buying the country’s crude even before sanctions are imposed on Nov. 4, Bloomberg reported on Thursday. India and China’s combined purchases of Iranian oil could drop about 23 percent to almost 1 million barrels a day amid the US restrictions, ESAI Energy said. OPEC is set to discuss the impact of the decline in Iranian crude on global energy markets when it meets in December — more than a month after the oil sanctions come into effect. “A sudden drop in Iranian crude shipments from the market will cause big shortages and a negative impact on oil prices,” he said, referring to a possible increase in prices,” Alaa Al-Yasiri the head of Iraq’s state-oil marketer SOMO, told Reuters on Wednesday. “It’s very difficult to predict what’s going to happen in next OPEC meeting but producers must find ways to make up for Iranian crude that the market will lose. The major issue during the next OPEC meeting will be are producers really ready to pump more oil to compensate Iran’s share?” Ongoing concerns over supplies from Venezuela as well as declining US oil inventories have stengthened claims that the global oil market is tightening once again. US commercial crude inventories fell by 2.6 million barrels in the week to Aug. 24, to 405.79 million barrels, the Energy Information Administration said on Wednesday. That was more than forecast. Still, current US sanctions on Iran are unlikely to stop Iranian oil exports completely, a long-time adviser at Saudi Arabia’s Energy Ministry said on Tuesday, adding Iran would be unable to close the straits of Hormuz and Bab Al-Mandab even partially. Speaking at an oil conference in the Norwegian city of Stavanger, Ibrahim Al-Muhanna said that Iran would be the first to lose out from any move to block those major shipping routes and that any such action would trigger further sanctions on Iran. Iran has said if it cannot sell its oil due to US pressure, then no other regional country will be allowed to do so either, threatening to block the Strait of Hormuz. “The amount of oil going through the Strait of Hormuz is so large. There’s more than 18 million barrels a day, about two-thirds of world maritime oil trade. Meaning, cutting oil from there will lead to an acute oil shortage and prices will skyrocket,” Muhanna said.