HOUSTON, April 28 (Reuters) - Chevron Corp (CVX.N) has stepped up sales of Venezuelan crude oil to rival U.S. refiners, adding PBF Energy Inc (PBF.N) and Marathon Petroleum Corp (MPC.N) to its list of customers for the crude, vessel tracking and loading schedules showed. Chevron, the last big U.S. oil producer still operating in U.S.-sanctioned Venezuela, has increased exports of the crude since January. So far in April, it has loaded about 148,000 barrels per day (bpd) of oil at Venezuelan ports, with cargoes going to at least three other U.S. refiners, besides Chevron's own refinery. In mid-April, Chevron sold about 550,000 barrels of Venezuelan crude to PBF for its 185,000-bpd Chalmette refinery, near New Orleans, U.S. Customs data on Refinitiv Eikon showed. Chevron has sent Venezuelan crude to its 369,000-bpd Pascagoula, Mississippi, refinery and this month shipped a cargo to a Bahamas oil-storage terminal, PDVSA's schedules showed.

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