Moscow is exploring a plan to merge its three largest oil companies into a single mega oil producer, The Wall Street Journal reported Saturday. Under the merger, state-backed Rosneft Oil would absorb Gazprom Neft—a subsidiary of the natural gas giant Gazprom—and Lukoil, sources familiar with the discussions told The Wall Street Journal. The deal would see the new company become the world’s second-largest oil producer after Saudi Arabia’s Aramco, and would pump nearly three times Exxon Mobil’s output. It would allow Russia to charge customers from India and China higher prices, according to The…