Downer New Zealand have apologised and donated $10,000 to Starship Hospital after contractors damaged baby burial plots at Manukau Memorial Gardens this week.
About 170 plots in the children's section of the cemetery had their flowers and small adornments - such as trinkets and toys - broken during regular maintenance work.
Downer chief executive Steve Killeen says he was "personally troubled" by the disrespect shown by his staff and apologised to the families of the children and to Auckland Council.
"This was a one-off, careless act and by no means represents the responsibility our 5000 employees accept every day in providing essential frontline services to our local communities," he said.
Downer would provide fresh flowers for the children's area of the cemetery and make the donation to Starship.
Auckland Cemeteries manager Catherine Moore said the damage was unacceptable and disappointing.
"We appreciate that this will be distressing for families, and we will ensure this will be managed with sensitivity and care."