BORDEAUX (AFP) - Maritime experts on Monday (Feb 1) began a final attempt to tow a tilting uncrewed cargo ship and stop it from crashing into France's picturesque Atlantic coast.

The Panamanian-registered Modern Express is currently 50km south-west of the beaches of the Bay of Arcachon.

Unless rescue teams can successfully attach a tow line, the 164m-long ship is expected to hit the coast at some point between Monday night and Tuesday night.

"Towing operations have begun. Four experts from SMIT Salvage are on board the vessel," the local maritime authorities said on its Twitter account.

The experts from the Dutch company which specialises in helping ships in distress were helicoptered onto the vessel, which is tilting dangerously at 40 degrees to 50 degrees and being buffeted by large waves.

"The difficulty is a combination of several things: the wind, the swell and the angle of the boat which is like climbing a mountain, but which is moving," a spokesman for Smit Salvage told AFP over the weekend.

The team managed to land on the ship on Saturday and attach a tow line between the Modern Express and a towing ship, but it snapped due to the movement of the vessels in the rough seas.

On Sunday heavy winds and waves of nearly six metres high prevented further rescue efforts.

"The wind has gone down, to 15-20 knots, but there are still swells of about 3m," a spokesman for the local government's maritime office said on Monday.

The Modern Express was carrying diggers and 3,600 tonnes of timber from Gabon in west Africa to the port of Le Havre in Normandy.

Around 300 tonnes of fuel remain in its tanks, but French authorities said there was a limited risk of pollution in the event of a crash.

A clean-up vessel was at the scene just in case.

The ship's crew sent a distress signal last Tuesday after the vessel listed strongly to one side, probably due to its cargo coming loose in the hull.

The 22 crew were evacuated by helicopter as they clung to the ship in dramatic scenes.

The attempt on Monday to tow the ship will be the fourth and final effort.

If experts manage to tow the vessel, it will likely be taken to a port on the northern coast of Spain.

However if the operation fails and the Modern Express washes ashore on the coastline of the Bay of Arcachon, it will likely be dismantled or cut up, rather than refloated.

The French coastline was hit hard in 2002 by the sinking of the Bahamian-flagged oil tanker the Prestige off the coast of Spain, which was carrying 77,000 tonnes of fuel.

The fuel polluted some 1,000km of French and Spanish coastline.