Description Big oil just got bigger with Japan's JX Holdings. The integrated energy holding company combines the businesses of two of the country's top oil refiners Nippon Oil and Nippon Mining Holdings, which merged in April 2010 to become a powerhouse with diverse operations in petroleum refining and marketing, oil and natural gas exploration and production, and metals (mainly copper). JX Holdings has total proved reserves of more than 44 million barrels of oil and natural gas liquids and 1.3 billion cu. ft. of natural gas. Its refineries have the capacity to process roughly 1.7 million barrels of crude oil per day, representing more than a quarter of the total amount of crude oil processed per day in Japan.