Australian shipbuilder Austal has confirmed it is nearing an agreement over a ferry order from Trinidad and Tobago.

It was responding to reports from the Caribbean that prime minister Keith Rowley had authorised the purchase of a fast passenger vessel from the yard.

"Austal looks forward to negotiating and resolving terms for the purchase of this vessel as quickly as possible," it said.

"In the meantime, this initial announcement will trigger the release of a down payment which will allow design of the vessel to commence and for initial long lead materials to be procured."

The vessel will be a 94-metre catamaran for operation between the islands of Trinidad and Tobago.

It is a variant of the two 109-metre high speed catamarans currently in production at Austal.

Contract finalisation is not expected for several weeks.