Telstra boss David Thodey is stepping down after six years in the job, to be replaced by the company’s finance chief Andrew Penn.

Thodey, 60, has been chief executive of the telecommunications giant since 2009 and has been widely credited with turning the business around after the turbulent reign of his predecessor Sol Trujilo.

He also led the company through difficult negotiations with the federal government over the NBN.

Telstra Chairman Catherine Livingstone paid tribute to Thodey, noting the company’s market value had more than doubled to $80 billion during his tenure.

“David has been an outstanding chief executive for our customers, shareholders and employees,” she said.

“His passion for customer service and instigating true cultural change has had an enormously positive effect on our company, which has been reflected in our financial performance in recent years,” she said.

Penn, 51 who is currently Telstra’s chief financial officer, will take over the reins to Australia’s biggest telco from May 1, but Livingstone said Thodey would remain “available” to the company until August to help smooth the transition.