Telstra is remaining tightlipped about Fiona Balfour's resignation as chief information officer (CIO).

After only 10 months in the job, Balfour made her resignation public this week.

Balfour's surprise departure led to an e-mail being issued to Telstra staff stating that she left the company to "pursue other opportunities."

The e-mail, from the telco's chief operations officer (COO) Greg Winn, implies that Balfour is planning to take up a new position although Telstra was unwilling to elaborate on Balfour's employment contract and why it came to such a premature end.

Telstra spends more than $1.5 billion each year on IT and Balfour was charged with overseeing a massive consolidation project at the telco which included the implementation of a new billing system and customer service platform.

Balfour's departure follows the resigation of deputy CIO Vish Padmanabham less than six months ago. No replacement was sought as Telstra abolished the position, leaving Balfour to oversee a five year IT overhaul at the telco.

Telstra will spend $11 billion on capital over the next four years rationalising its networks and IT systems under CEO Sol Trujillo.

Balfour will be temporarily replaced by former Accenture partner, Tom Lamming, who has been Winn's IT adviser for the past 18 months.

"I regret Fiona's decision and wish her well for the future. I particularly want to thank Fiona for her contribution leading the IT Services (ITS) team in the past year and for putting in place the best people and infrastructure to support the IT transformation program," Winn said. "The ITS leadership team will report to our business transformation adviser, Tom Lamming, in the interim."

Gartner telco analyst Geoff Johnson said Balfour has been under a lot of pressure to rationalize the telco's IT systems.

Also, Johnson said Winn and Trujillo are obviously comfortable with Lamming.

He said Lamming has a history of rationalizing systems and Winn has pushed hard to consolidate IT systems from 1200 down to 300.

"Telstra has invested billions in these systems and they need to be rationalised; these IT systems are big animals to run," Johnson added.

Prior to joining Telstra, Balfour spent 14 years at Australian airline Qantas where she inked major outsourcing deals.

- with Darren Pauli