HOUSTON, March 3 (Reuters) - Sales of Venezuelan crude to the United States fell slightly to 637,105 barrels per day (bpd) in February due to lower exports of upgraded Orinoco belt oil, according to Thomson Reuters Trade Flows data.
State-run oil company PDVSA and its joint ventures sent 40 crude cargoes to its customers in the United States last month, including Citgo Petroleum, Valero Enery, Phillips 66 , Chevron Corp and PBF Energy.
Spot crude sales were also made to Lukoil Panamericas and Axeon Specialty Products, according to the data.
Venezuela and half a dozen private partners operate four crude upgraders that can convert up to 620,000 bpd of extra heavy oil into exportable grades.
When upgraders are not fully operating, PDVSA increases purchases of heavy naphtha and light crudes to dilute its extra heavy output. In 2015 it bought some 110,000 bpd of diluents, according to its imports and exports internal reports.
In February, larger sales of blends made with imported diluents could not offset an overall decrease of 1 percent in shipments to the United States, the third monthly decline in a row according to Thomson Reuters data.
The company received three 500,000-barrel cargoes of heavy naphtha from trading firms Helsinge and Citizens Resources, according to its report, and it also imported a 500,000-barrel cargo of U.S. WTI crude at its Bullenbay facility in Curacao in late February.
PDVSA launched a tender to import a gasoline blend stock cargo and a catalytic naphtha cargo last month while its largest refining center, Paraguana, was restarting some of its operational units after a blackout. But the tenders were not awarded, traders said.
Reporting by Marianna Parraga; Editing by Tom Brown