Australian shipbuilder Incat has clinched a new ro-pax order worth $130m.

The 130-metre vessel for Uruguay's Buquebus will be the world's biggest aluminium ship, the yard told AAP.

It will operate between Argentina and Uruguay.

Incat founder and chairman Robert Clifford said his company will spend six months designing the vessel, with delivery expected in three years.

It will likely be 13,000 gt, carrying 2,100 passengers and 220 cars.