China Petroleum & Chemical or Sinopec (HKG:0386, SHA:600028) agreed with Aramco to expand a petrochemical complex of their joint venture, Yanbu Aramco Sinopec Refining Company or Yasref, in Saudi Arabia, according to Aramco's Wednesday press release.

Under the project, a large-scale mixed feed steam cracker with an annual capacity of 1.8 million tons and an aromatics complex with associated downstream derivatives with a yearly capacity of 1.5 million tons will be integrated into the existing Yasref complex.

Aramco owns 62.5% of Yasref, while Sinopec holds 37.5%.

Sinopec's Hong Kong shares slipped 1% in recent trade.