The order consists of one vehicle-passenger ferry and one passenger ferry, and is the company's third contract with Austal since 1997.
The vessels are intended to operate from Guadeloupe to the Caribbean islands of Marie Galante, Dominique, Martinique and St Lucia, where they will provide an important inter-island link for tourism and trade.
The vehicle ferry will have the capacity for 364 passengers and 10 cars.
The passenger ferry will have the capacity for 437 passengers.
Both vessels will have a maximum speed of more than 32 knots and are also designed to carry cargo.
L'Express des Iles currently operates Austal-built ferries "Gold Express" and "Silver Express", which were delivered in 2005.
Compared to the four-engine arrangements of L'Express des Iles' previous deliveries, the new vessels will each be powered by two MTU 16V4000 M71 diesel engines driving Kamewa 71 SIII waterjets.
The new vessels will be built at Austal's Western Australian facility and are scheduled for delivery in mid-2011.
Austal has an established service presence in the Caribbean region with a dedicated vessel repair and maintenenace hub located in Trinidad and Tobago.
Austal Service personnel are currently on location in Martinique performing maintenance work on "Silver Express" and "Gold Express".
Austal is also building four 41-metre high-speed passenger ferries for the National Infrastructure Development Company Limited (NIDCO) in Trinidad and Tobago, scheduled for delivery later this year.