CHINA signed a 30-year contract with Russia yesterday to buy natural gas from eastern Siberia. The deal, said to be worth US$400 billion, was the culmination of more than a decade of negotiations.

Russian state gas exporter Gazprom will start supplying gas to China National Petroleum Corp in 2018 via a new eastern pipeline linking the two countries. Annual supply volumes will grow gradually until they reach 38 billion cubic meters, CNPC said. That’s equivalent to about a quarter of China’s current annual demand.

The deal signed in Shanghai between the two companies was witnessed by Chinese President Xi Jinping and his Russian counterpart Vladimir Putin. The agreement was clinched just hours before Putin ended a two-day visit to Shanghai, where he attended a regional security summit.