China Petroleum & Chemical Corp (Sinopec) and Kuwait Petroleum Corp have started building their joint refining and petrochemical complex in the southern Chinese province of Guangdong, the top Chinese oil refiner said.

The 59 billion yuan ($9.3 billion) project, including a 300,000-barrel-per-day refinery and a 1-million-ton-per-year ethylene cracking unit, was expected to come on line in 2015, Sinopec said in a press release.

The National Development and Reform Commission, a powerful ministry in charge of major project approvals, gave its nod for the project in March.

KPC has said it is still looking to partner with an international oil company for some of its 50% stake in the project in Zhanjiang in western Guangdong.

The project will secure Kuwait, the world's seventh-largest crude exporter, a stable outlet for its oil as it aims to more than double crude exports to China to 500,000 bpd, while giving the world's second largest oil buyer a steady supply as demand keeps pace with solid economic growth.

In 2009, KPC briefly tapped potential investors Royal Dutch Shell and Dow Chemical, but the companies did not commit to form a consortium.

Kuwait said in April that it was in talks with BP and other major energy companies over a possible role in the refinery project.