The Organization of the Petroleum Exporting Countries has delayed completing its internal report on long-term strategy as tensions deepen among members over an extended oil-price slump, according to delegates to the group. The disagreements could set for the stage for a tense OPEC meeting next month, when oil ministers from the group’s 12 members will gather in Vienna to decide on production levels. Prices for Brent crude, the international benchmark, have fallen to below $50 a barrel after years above $100, blowing a hole in the national budgets of OPEC members that rely heavily on oil exports. OPEC’s long-term strategy report was expected to be made final Wednesday at an OPEC staff-level meeting in Vienna before being submitted for ministerial approval next month. But attendees at the meeting said OPEC delegates—who represent national governments with competing interests—couldn’t agree on language defining the group’s long-term mission. Algeria, Iran and Venezuela—which […]