Mr Stock, who takes over the reins in the firm's centennial year, is Naylor Love's chairman and he will be replaced by Wanaka businesswoman Anne Urlwin, who has been on the Kordia board since June last year.
The changes were the result of the retirement of Naylor-Love managing director Trevor Kempton.
He had held the position for eight years and worked for the company for the last 23 years.
Mr Stock is an electrical engineer.
Before his role with state-owned broadcasting and telecommunications business Kordia, he worked throughout Asia and North America in the design and construction of geothermal power stations.
On returning to New Zealand, he was chief executive of electrical contracting company United Gooder, now known as UGL, and electrical infrastructure contractor Northpower.
Mr Kempton said Mr Stock's proven ability to successfully grow businesses and manage change, would be valuable to Naylor Love.
Mr Stock would continue to live in Auckland, but spend the weeks in Dunedin.
"There is no intention to move our head office from Dunedin. It will remain the registered office of the group and our group support and corporate administrative team will continue to be based here," he said.
Meanwhile, a book recording a century of Naylor Love history is being launched at a function in the city tonight.
A Bob Both Ways, written by Rosemarie Patterson, tells how Hugh Naylor and James Love each established their own building firms in 1910, which were amalgamated in 1969 to form Naylor Love.
