Iran gave OPEC the green light on Friday to reduce oil output by around 0.8 million barrels per day from 2019 after finding a compromise with rival Saudi Arabia over a possible exemption from the cuts, an OPEC source said. Tehran has emerged as a key sticking point for a deal but sources said the difficulties were now in the past and OPEC was refocusing on talks with non-member producers led by Russia to reduce supplies and prop up oil prices. "Yes, Iran agreed in principle," the source said. OPEC will propose that non-member producers contribute an additional 0.4 ...