Leighton Holdings subsidiary Thiess has taken control of NBN contractor Silcar, buying out former joint venture partner German engineering giant Siemens' half stake in the group.
It comes amid reports that Silcar's acting chief executive - who is Thiess' general manager of strategy - has axed up to eight senior managers from the business as it is hit with tens of millions of dollars in writedowns building the NBN.
Thiess said the acquisition of Siemens' 50% stake in Silcar was "agreed so that both companies could better focus their respective strategic portfolios".
The Australian reported that the departure of up to eight senior workers, who reported to the head of Silcar's NBN projects, Dan Birmingham, have coincided with the exit of Silcar chief executive Peter Lamell, who quit his post in May.
Silcar is rumoured to be facing losses of up to $60 million and could be looking to opt out of its NBN contracts to avoid more losses, The Australian said.
Workers who have left include national construction manager Dave Letizia, operations manager Luke Halley, operations manager Glen McGarry and design manager Ewen McKenzie.
A spokesman for Silcar would not confirm or deny the departures.