China and Japan have reached an agreement to jointly develop natural gas fields in the East China Sea, historically a major point of contention between the two countries, the Wall Street Journal reported. Under the terms of the agreement, Japanese companies will be allowed to to invest in and claim proportional profits from several Chinese-run projects at the Chunxiao oil fields, which Japan calls Shirakaba. Two Chinese companies are already drilling at Chunxiao and the area around the Longjing oil fields, both of which lie close to the median line dividing the two countries’ waters. The two countries will also jointly explore the area for new sites. Japan and China held several rounds of talks concerning the oil fields since 2004. China had previously rejected Japan’s proposal for joint gas exploration.