¬†OPEC and its allies look set to keep their deal on cutting oil supplies for the rest of 2018, five sources familiar with the issue said, although some producers are starting to worry that high prices may be giving too much stimulus to rival output. OPEC, Russia and several other non-OPEC producers have curbed output since January 2017 to erase a global glut of crude that had built up since 2014. They have extended the pact until the end of 2018, and meet on June 22 to review policy. The deal has boosted oil prices LCOc1, which topped $71 a barrel this year for the first time since 2014. They were close to $70 on […]