With about 30 per cent of the tender required to go to local firms, Mr Mason said he was "enthusiastic" about the future.
"Infracon has a fantastic record, with excellent resources and I'm really proud of how our staff are carrying on doing great work, despite everything."
Mr Mason said about 90 staff were working for Infracon in the Tararua while others were employed in Hawke's Bay.
"Staff are obviously a little unsettled at the moment," he said.
"This job is always challenging, but Infracon is a good company with great people."
Tararua District Mayor Roly Ellis, an interim director of Infracon, has said the decision to go with Downer was simply a matter of good quality roads at the right price (for ratepayers).
But for Infracon staff fearing for their jobs, Mr Ellis' words have a hollow ring.
"It's ironic the mayor has sympathy for those losing their jobs because of the closure of Postie and fair enough, but he seems dismissive of job losses at Infracon," a staff member who wants to remain anonymous, wrote in a letter to the Dannevirke News.