Mobile, Alabama| Sparks are flying inside the Austal shipyards on the banks of the Mobile River as workers weld metal. They’re also flying about the ASX-listed company’s future and the prospect of a new owner that could change their lives – and Australia’s defence sector – forever.

Perth-headquartered Austal’s business in the United States has boomed since 2004, transforming from a 25-metre boat servicing offshore oilfields into one with an $11 billion order book. Now, as first reported by The Australian Financial Review’s Street Talk column, it is up for sale, and the likelihood of a private equity firm taking over is raising big questions.