Oil rose to its highest level in a year after Russian president Vladimir Putin said that he backed efforts for a production cap in the clearest sign yet that the country would join any global supply pact.  Speaking at an energy conference in Istanbul, Mr Putin said he hoped that the Opec producers’ group would agree on output curbs for member nations at its next ministerial meeting in November.  Opec countries reached an agreement in Algiers last month to curb production but details for a binding deal to reduce supply — the first since the financial crisis — still need to be finalised.  It was understood that should Opec come to a consensus, non-Opec producers such as Russia would also be asked to join any co-ordinated supply curbs to stem the two-year price slide.   The drop in prices by more than half since mid-2014 had triggered the longest period of investment decline in 45 years, Mr Putin said. The threat of “unpredictable jumps” in prices loomed, he sai