DUBAI- Oil producer Saudi Aramco signed a memorandum of understanding (MoU) with China's Zhejiang Free Trade Zone in eastern China to expand downstream investment, the company said in a statement on Thursday.

Saudi Aramco, the world's top oil exporter, bought a 9% stake in a 800,000 barrel-per-day complex built by Zhejiang Petrochemical, majority owned by private firm Zhejiang Rongsheng Holding Group, in the free trade zone in February.

The MoU includes a long-term crude oil supply agreement and the ability to utilise Zhejiang Petrochemical's crude oil storage facility to serve Aramco's customers in Asia.

The agreement will also allow the parties to evaluate potential opportunities for investment in other areas, the statement said.

These areas include refining, petrochemical production, storage, oil and natural gas trading, retail, and oil products distribution within the free trade zone, it said.

(Reporting by Muyu Xu and Chen Aizhu; editing by Jason Neely) ((muyu.xu@thomsonreuters.com; +86 010 66271298;))