Oil prices rallied on Tuesday, after one of their biggest selloffs this year, but looked vulnerable to further falls after China’s stock market took another tumble and Greece moved closer to leaving the euro zone. Investors also kept a close eye on talks in Vienna over Tehran’s nuclear programme that could lead to increased exports of Iranian crude at a time of global oversupply. Brent crude for August LCOc1 was up 70 cents at $57.24 a barrel by 0810 GMT (4.10 a.m. EDT), following a more than 6 percent drop in the previous session. On Monday, Brent briefly touched $56.38, its lowest since April 10. U.S. crude CLc1 traded at $53.10 a barrel, up 57 cents from the settlement on Monday, when it reached levels last seen in mid-April. Despite the rally, most analysts were bearish. “Macroeconomic headwinds are rising — be it in the form of the […]