U.S. oil industry regulators opened a dialogue with OPEC in talks that could help foster a truce between the world’s three largest oil producers and potentially resolve a Saudi-Russian price war that has devastated oil markets in recent weeks, according to people familiar with the matter. Mohammed Barkindo, secretary-general of the Organization of the Petroleum Exporting Countries, spoke Friday with Ryan Sitton, the Texas railroad commissioner who oversees the U.S.’s biggest oil patch, these people said. …