LONDON: Iran and Syria have resumed working together to fight Western sanctions on their oil as shipping records showed two Iranian vessels have delivered diesel to Syrian ports over the past week, the first fuel shipments from Iran in about three months.

The first tanker reached Syria with a 35,000 tonne delivery of diesel, which it discharged last week, and then loaded a similarly sized cargo of Syrian gasoline, a shipper said.

On Tuesday, satellite tracking data showed the vessel was heading back for Egypt's Suez Canal.

Syria's economy is suffering because supplies of diesel, or gasoil as it is known in the industry, have grown scarce since tight EU sanctions in March forced a halt in exports from Russia.

Gasoil is needed to power heavy vehicles, such as those used in agriculture or by the armed forces.

Although Syria is an oil producer, its refineries produce light-end products such as gasoline and naphtha, making the country reliant on imports to meet its needs for heavier fuels such as diesel.

Providing at least some short-term relief, the combined deliveries at the end of June aboard the two Iranian tankers amounted to around 100,000 tonnes, according to records provided by a shipper and satellite tracking data.

A third vessel appeared to be on its way to Syria along the same route, but then dropped anchor off the coast of Port Said in Egypt, shiptracking data showed.

At current market prices, the two shipments are worth around $90 million in total.

Syria's need for gasoil makes it a perfect fit to swap with Iran, which produces plenty of diesel but has struggled for years to find sufficient supplies of gasoline, the fuel used in most civilian cars.

The second vessel was still berthed at the Syrian port of Banias on Tuesday, and expected to load a combined cargo of heavy and light crude oil from two Syrian oil terminals.

It was not clear who would purchase the cargo. Both Iranian and Syrian crude oil is subject to Western sanctions, and Iran itself is already facing a dramatic and potentially crippling cut in its own exports due to the embargo, which came into force on Sunday.

The last exchange of petroleum products between Syria and Iran took place at the end of March and into April, when the same vessels made the journey from Iran to Syria and back.