Adds no immediate reply from the companies in paragraph 4

By Georgina McCartney and Arathy Somasekhar

HOUSTON, Jan 21 (Reuters) - Valero VLO.N bought a cargo of Venezuelan crude oil, two sources said on Wednesday, the first deal by a U.S. Gulf Coast refiner struck as part of Washington's deal with Caracas to buy up to 50 million barrels of the South American country's crude.

Valero bought the crude from trading house Vitol, one of the two sources said. The crude was traded for delivery to the U.S. Gulf Coast at a discount of about $8.50 to $9.50 to Brent crude LCOc1, two sources said.

While Valero has been a buyer of Venezuelan crude through the Venezuelan state oil company's partner, Chevron CVX.N, the deal would mark the first purchase from trading houses that were only authorized this month to market crude from Venezuela.

Valero and Vitol did not immediately reply to requests for comments.

Offers of Venezuelan flagship Merey heavy crude to U.S. refiners began last week at a discount of between $6 and $7.50 per barrel to Brent.

Before sanctions were imposed in 2019, several large U.S. Gulf Coast refineries bought and processed about 800,000 barrels per day of Venezuela's heavy oil, according to U.S. government data.

(Reporting by Georgina McCartney and Arathy Somasekhar in Houston; Editing by Himani Sarkar and Christian Schmollinger)

((Georgina.McCartney@thomsonreuters.com; Twitter/X @G__McCartney; +1 (832) 577-3987))