Naphtha, where prompt supplies of open-specification grade are currently ample, is also used as a blending component for gasoline other than for the production of petrochemicals.

Supplies of heavy full-range naphtha were less ample versus the open-specification grade.

South Korea's GS Caltex on Tuesday bought heavy full-range naphtha for second-half August delivery at premium levels (C&F) but the exact range could not be directly confirmed as buyers do not typically comment on their deals.

The GS Caltex purchase was made on the same day as SK Energy where the latter paid about $9 a tonne premium to Japan quotes on a C&F basis for heavy full-range naphtha.

While heavy full-range grade prices have been holding in premium levels, benchmark open-specification naphtha spot prices have been trapped in discounts since May in South Korea.

Gasoline demand in the West in the meantime was firm.

Exports from Europe to the US East Coast had risen in recent days to plug a supply gap after the 335,000 barrel-per-day Philadelphia Energy Solutions Inc refinery was affected by a massive fire on June 21.

OTHER NEWS: Venezuela's oil exports recovered in June from a sharp drop the month before, helped by increased deliveries to China, which is now state-run oil firm PDVSA's primary destination for its crude, according to company records and Refinitiv Eikon data.