China Petroleum and Chemical Corp, the world's largest refiner by volume, has signed an agreement with Russian petrochemical company Sibur on the Amur Gas Chemical Complex (Amur GCC) in Moscow, the company said on Thursday.

The agreement was signed in the presence of Chinese President, Xi Jinping, and Russian President, Vladimir Putin.

Under the agreement, the company, also known as Sinopec, will hold a 40 percent stake in Amur GCC.

"Investing in Amur GCC marks another one of our efforts to deepen cooperation between the two parties since we became a strategic investor of Sibur," said Dai Houliang, Sinopec chairman.

"Leveraging our best practices and advantages, we are committed to making this partnership represent regional energy cooperation in the downstream petrochemical sector."

"This partnership will enable both parties to develop common expertise and experience to maximize the efficiency of new large-scale projects," said Dmitry Konov, chairman of Sibur's management board.

Dai and Konov on June 5 in Moscow signed an industry cooperation agreement and ZapSibNeftekhim product-distribution agreement, which commits to strengthen strategic partnerships in China, Russia and other countries, while exporting to China polyethylene produced by ZapSibNeftekhim.