SINGAPORE (Reuters) - Chinese refiner Rongsheng Petrochemical has bought 4.4 million barrels of Oman and Canadian crude oil exported from the recently expanded Trans-Mountain pipeline for delivery in October via a tender, trade sources said on Wednesday.

These include 2 million barrels of Oman crude and four 550,000-barrel cargoes of Canadian Access Western Blend (AWB) crude, they said.

CNOOC, BP, Totsa - the trading arm of TotalEnergies - and PetroChina sold the AWB crude cargoes at discounts of about $6 a barrel to ICE Brent, stable from the previous month, traders said.

The deal marked CNOOC's first sale of TMX crude in Asia. The Chinese state energy major has oil sands and shale gas assets in Canada.

Last month, Rongsheng also purchased four AWB crude cargoes for September delivery.

(Reporting by Florence Tan, Editing by Louise Heavens and Miral Fahmy)