Telstra chief information officer John McInerney has stepped down effective immediately, as the company plans to merge two IT divisions.

The company announced yesterday that its CIO had decided to pursue other work opportunities, and would not be back from several months' long-service leave.

McInerney had been working on the final stages of a new IT system for Telstra, including a customer billing system that the company had been striving to finish.

Chief operations officer Michael Rocca also said that Mr McInerney will be replaced by Ashley Lazaro, who has been acting in the role in Mr McInerney's absence.

He also announced changes in Telstra's technology unit.

''This change comes as we review our IT structure and effectiveness, and continue to integrate our network and information technology expertise - including an integrated strategy for managing network and data centres within Telstra operations,'' said Mr Rocca.

''The lines between communications technologies - IT and network - are converging and this will continue as network virtualisation becomes more and more common. Our business will need to adapt and change to meet the challenges of the new converged world."

Senior executives have successively exited Telstra in the past half year, including broadband and media boss Justine Milne, former head of Telstra Country Wide Geoff Booth, and Mr Rocca's predecessor, Greg Winn.