Saudi Crown Prince Mohammed bin Salman said that the Organization of Petroleum Exporting Countries (OPEC) and Russia are working on a long-term deal to cooperate on oil supply curbs. “We are working to shift from a year-to-year agreement to a 10-20 year agreement,” the crown prince told Reuters in an interview in New York. “We have agreement on the big picture, but not yet on the detail,” he said. The crown prince also said a flotation of 5 percent of Saudi oil company Aramco could take place at the end of 2018 or early 2019, depending on market conditions. Saudi Arabia recruited Russia and other producers to collaborate with OPEC when oil prices dropped. Energy Minister Khalid al-Falih expected last week that oil producers would extend output curbs into 2019.