Venezuelan oil company PDVSA has sent an aframax tanker to take crude off a listing floating storage and offloading vessel viewed as a major environmental risk.

The 99,000-dwt Icaro (built 1993) reached the 208,000-dwt FSO Nabarima (built 2005) on Tuesday evening in the Corocoro oil field in the Gulf of Paria, located between Venezuela and the island of Trinidad, according to Refinitiv Eikon data.

Environmental campaigners have been calling for urgent action after the unit listed 25 degrees to starboard this week. The Venezuelan government has said the list has been corrected, however.

The FSO has 1.3m barrels of crude on board and hit the headlines last month when three metres of water was pictured inside the vessel.

Reuters cited a source close to the operation as saying some of the crude on board will be transferred onto the aframax.

Sanctioned ship

Icaro is one of six PDVSA-connected tankers sanctioned by the US in December, over alleged oil shipments to Cuba.

Reuters reported earlier in the week that a work crew is replacing Nabarima's valves.

The Venezuelan oil ministry has previously said the oil on board would be lightered.

Italian refiner Eni owns 26% in Petrosucre, the FSO's operator controlled by PDVSA.

An Eni spokesperson said last week that the company was seeking to offload crude from the vessel, and had requested a "green light" from the US "in order to prevent any sanctions risk".

Last month, TradeWinds reported that disaster had been averted after Eni said the unit was stabilised and had resumed operations. "The conditions of the FSO are stable and a recent water leak has already been solved," the refiner said at the time.