The National Australia Bank (NAB) today confirmed it has inked a three year outsourcing deal with IBM Australia to manage more than 30,000 desktops.

The incumbent Telstra refused to comment on losing the deal which is worth about $100 million a year.

NAB made the decision to move to a new provider although it had an option to extend its contract with Telstra for another two years.

While the bank was unwilling to formally disclose the cost of the deal, the move confirms rumours that had been circulating for years about an unhappy relationship between NAB and Telstra.

However, despite making the shift to IBM to manage its desktops, Telstra is still responsible for the bulk of NAB's outsourcing arrangements.

Earlier this year NAB awarded a five year $600 million contract toTelstra for managed telephony services, which includes the implementation of IP telephony infrastructure across all of its branches.

NAB believes the progress made to date on its IP project has been successful but the desktop transition to IBM may take up to six months.