LONDON (Reuters) -The OPEC+ group of oil producers is discussing output cuts of more than 1 million barrels per day (bpd), OPEC sources said, and voluntary cuts by individual members could come on top of that, making it their largest cut since 2020. The group is set to meet on Oct. 5 in Vienna — in person for the first time since March 2020 — against a backdrop of falling oil prices and months of severe market volatility which prompted top OPEC+ producer, Saudi Arabia, to say the group could cut production. OPEC+, which combines OPEC countries and allies such as Russia, has been gradually ra…