The potential buyer of an Austal-made ferry that has been on the market for four years is expected to seek another three months to decide on the deal.
English Channel vessel service provider Condor Ferries is awaiting a new operating licence before it can make a call about buying the 102m trimaran from Austal.
The boat is estimated to be worth up to $100 million.
Condor Ferries is understood to be the company that signed an option-to-purchase contract in January.
The deal is set to expire at the end of this month.
Without confirming the buyer's identity, Austal chief executive Andrew Bellamy said the interested party was likely to extend the contract to September 30.
"I think it's most likely we'll finalise the deal in the first half of the next financial year," Mr Bellamy said.
"It looks to me like it's progressing more slowly than anyone would have liked," he said.
It is believed Condor Ferries may learn about its licence to operate beyond 2018 from the Channel Islands governments as early as this month.
The trimaran was built on spec at Austal's Henderson shipyard in the aftermath of the global financial crisis to keep it workforce occupied.
Since putting it on the market in 2010, the company has been unable to sell or secure a charter deal for the vessel.
In its half-year result in February Austal wrote down about $10 million from the value of the ferry.
Condor Ferries chief executive James Fulford last year said the ferry would cost about £50 million ($90 million).