The return of crude-oil prices below $50 a barrel is testing the unity of the Organization of the Petroleum Exporting Countries, which on Tuesday posted near-record levels of production even as low prices ratchet up pain for its members. In its monthly oil-market report, the 12-nation cartel of some of the world’s biggest oil producers said members pumped 31.51 million barrels a day in July—its highest level since May 2012 and representing an increase of 101,000 barrels a day, compared with the previous month. That is more than 1.5 million barrels a day above the group’s stated output ceiling of 30 million barrels a day—a level OPEC endorsed at its last gathering in June . In the past, OPEC has bolstered prices by restraining output. But in the current downward price spiral, the group has kept pumping, a move aimed at protecting market share, instead of prices. The strategy […]