The Department of Defence has extended its decade-long IT support deal with Unisys to allow itself more time to replace its massive distributed computing contracts.

The $46.4 million contract extension will provide end user support services to some 100,000 users across Defence's more than 460 military bases and offices around Australia until the end of October 2019.

Unisys has held the IT support deal under the moniker of ‘regional ICT services’ since 2008. It is one half of Defence’s distributed computing bundle of work, which is estimated to be worth in excess of $600 million.

Fujitsu holds the other half of the bundle in a relationship that spans two decades. Fujitsu's latest extension was signed in November 2016, and takes the agreement out to April 2019.

Unisys' contract extension comes just months after Defence made good on its long-anticipated plan to refresh the distributed computing deals held by the pair.

It went to market in October looking for new deals across three separate service towers: national deskside support, service desk, and service integration and management, which it hoped would be in place by June this year.

Defence had originally hoped to put the combined outsourcing contract to the market back in 2015, but it put the project on hold while it dealt with a “significant” IT program of work.

A spokesperson told iTnews the new extension would “give Defence more time to thoroughly complete the tender evaluation process”.

“The contract extension for Unisys is to allow Defence sufficient time to complete the evaluation and commercial arrangements” for the new deals, the spokesperson said, including transition.