SINGAPORE, Aug 23 (Reuters) - Chinese refiner Rongsheng

Petrochemical has bought 1.65 million barrels of

Canadian crude oil to be exported from the Trans-Mountain

pipeline for delivery in November, including its first cargo of

Kearl Lake crude, trade sources said on Friday.

The mega refiner has become a regular buyer of the heavy

sour Canadian crude since the newly expanded Trans-Mountain

pipeline started operations in May.

The rare 550,000-barrel cargo of heavy sour Kearl Lake crude

was sold by Exxon Mobil Corp ( XOM ), the sources said. One of

them added that the cargo was sold at a discount between $5.50

and $6 a barrel to ICE Brent.

Rongsheng Petrochemical also bought two 550,000-barrel

cargoes of Canadian Access Western Blend (AWB) crude from Totsa,

the trading arm of TotalEnergies, at discounts of

$5-$6 a barrel to ICE Brent, the sources said.

Kearl Lake crude has an API gravity of 19.5 and contains

4.1% sulphur. It is also a highly acidic grade, similar to AWB.

Companies typically do not comment on their deals.