Exclusive - Saudis threaten to raise oil output again as sparring with Iran returns

By Rania El Gamal and Alex Lawler DUBAI/LONDON (Reuters) - Old disputes between Saudi Arabia and rival Iran resurfaced at a meeting of OPEC experts last week, with Riyadh threatening to raise oil output steeply to bring prices down if Tehran refuses to limit its supply, OPEC sources say. Clashes between the two OPEC heavyweights, which are fighting proxy wars in Syria and Yemen, have become frequent in recent years. Tensions subsided, however, in recent months after Saudi Arabia agreed to suppor