Philadelphia Energy Solutions' (PES) 335,000 barrel-per-day (bpd) oil refining complex, the largest and oldest on the US East Coast, is set to permanently shut down after it was hit by a devestating fire on June 21.

Benchmark US gasoline refining margins gained over 16% since the fire at the plant which supplies around 55,000 bpd of gasoline to the region, according to consultancy Energy Aspects.

As a result, the economics for shipping gasoline from Europe to the US East Coast improved significantly in recent days, traders said.

A sharp rise in tanker freight rates is, however, weighing on the arbitrage, the traders said.

Around 18 tankers carrying a gasoline cargo of 37,000 tonnes, totalling 666,000 tonnes, or 5.62 million barrels, have been booked out of Europe on the transatlantic route in the first 10 days of July, according to shipping data obtained by Reuters.

Refinitiv Eikon data shows that Europe sent 1.3 million tonnes of gasoline to the US East Coast, also known as PADD 1, throughout the entire month of June, and 1.4 million tonnes in May.

Europe has traditionally supplied large volumes of gasoline to the US East Coast, but the flow on the transatlantic route decreased in recent years as US domestic production rose.