The US Navy has provided funding for Austal to build another two Littoral Combat Ships, the seventh and eighth vessels in a 10-ship program worth $US3.5 billion.
The funding for the two ships adds about $US684 million to Austal's order book, raising it to a record total of $3.3 billion.
Austal chief executive Andrew Bellamy said funding for the additional ships secured construction work at Austal's US shipyard in Alabama through to 2019.
"Our knowledge base in designing and constructing these revolutionary ships continues to grow as the LCS program matures, enabling better program outcomes for the US Navy and improved margins and returns for shareholders," he said.
Austal has five Littoral Combat Ships under various stages of construction at its shipyard in the US.
Apart from the LCS contract, Austal also has a $US1.6 billion contract from the US Navy to build ten 103-metre Joint High Speed Vessels (JHSVs), all of which are fully funded.
Two of these vessels have been delivered, with JHSV 3 scheduled to be delivered by the end of March. An additional three JHSVs are under construction.
Austal shares were off half a cent to 88.5 cents at 8.20am.