Teams from a salvage company and a French coast guard anti-pollution squad are to start Friday pumping fuel out of a Spanish cargo ship which has broken into three sections after a spectacular shipwreck in bad weather.

The operation will be a race against time as it must be carried out in the two hours of low tide and before new storms forecast for the weekend hit France's Atlantic coast.

The 20-year-old Spanish vessel split in two when winds and waves smashed it up against an artificial breakwater near the French port of Bayonne on Wednesday. The crew of 11 were rescued by helicopter in perilous conditions. Later, one of the segments broke into two.

Fearing a fuel leak, French authorities launched an emergency plan to deal with maritime pollution. Some 20 tonnes of fuel likely dispersed into the sea.

The coast guard teams, along with firefighters, salvage experts contracted by the ship's owner and the vessel's chief engineer plan to pump out the 60 to 70 tonnes of fuel found in the front part of the ship, which is washed up on a beach. The other two segments do not contain fuel tanks.

The operation will be "difficult," local mayor Jean Espilondo said, because the front end "is lying at a 15-degree angle under the force of the waves".

A probe has been opened into the accident. The crew members were being interviewed Thursday and Friday.

A source close to the investigation said the ship had come empty from Spain to pick up a cargo of ball-bearings.

As it tried to enter Bayonne's port late Tuesday it suffered an electrical malfunction that left it drifting for a while. On Wednesday, with power restored and two tugboats helping, it tried again to enter port but a new blackout occurred, leaving it helpless in the water, at which point it struck the breakwater.