On May 7, China National Petroleum Corporation and Japan's Nippon Oil Corporation signed a letter of intent in Tokyo in considering to create a refinery joint venture, which is capable of processing 115,000 barrels of crude oil per day. Headquartered in Tokyo, Nippon Oil is the largest petroleum corporation in Japan. The refinery joint venture will be the largest cooperative project between China and Japan in the energy field. CNPC signed another agreement with Nippon Oil on May 7. Under the agreement, the Japanese company will refine 3.5 million tonnes of crude oil for CNPC in fiscal year of 2008.  Nippon Oil has undertaken oil refining services for CNPC since 2004 with a daily capacity of 20,000 barrels. The new agreement will increase the daily oil refining volume to 70,000 barrels.