Telstra group executive, Robert Nason, will retire after playing a major role in the structural transformation of the company.
Nason, 60, was the Telstra executive responsible for establishing a multi-year, multi-billion dollar productvity program and led the introduction of the Net Promoter System into Telstra to drive focus on customer advocacy.
Telstra chief executive, David Thodey, said Nason had been a critical player in the company's shift in customer, market and employee perception and would be sorely missed.
"Robert has taken on many of our large, complex, difficult opportunities during the past five years and made them into strategic opportunities for Telstra and tangible benefits for our customers and shareholders," he said.
"He has been in tireless pursuit of wastes, inefficiency and frustration to make it easier for us to do business and easier for people to do business and easier for people to do business with us."
Nason said he felt the time was right to explore opportunities for non-executive director roles, having been part of such a significant improvement and change program for five years.
"While the task can never be regarded as completed, Telstra has made strong progress on the productivity and service agenda," he said.
"It has a deeply entrenched focus on improving the experience for our customers and a strong team capable of taking if forward."
Thodey said replacement arrangements for Nason would be determined in the near future.
He will continue his role for several months then provide transitional support and other assistance within the business.
He will also maintain his responsibilities with Foxtel, before leaving in October.
Nason joined Telstra in February 2010 from Tabcorp where he was managing director, wagering, responsible for the company's race wagering and media businesses, including sky channel and Sydney radio station 2KY.
He has also previously worked in executive roles at Electronic Data Systems, AT Kearney, Coopers & Lybrand and KPMG.