IBM has opened its fourth Australian data centre to meet growing demand for locally hosted cloud service Bluemix as well as the Watson cognitive computing platform.

Big Blue is hosting the point of presence in the 6MW Erskine Park, Sydney facility run by co-location provider Digital Realty. The data centre joins IBM's three existing Australian cloud data centres in Sydney and Melbourne.

Onshore hosting is important "because we know our enterprise clients want to keep their data local", according to Tony Armfield, vice president cloud for IBM Australia and New Zealand.

"More and more Australian organisations are tapping into the IBM cloud to gain a competitive edge in the cognitive era thanks to IBM’s combination of industry expertise, cognitive solutions and a data-first approach," he said.

Armfield would not be drawn on specific Australian customers driving the growth. However one high-profile account is Telstra, which used IBM’s cloud conference in Las Vegas in March to reveal it was shifting one in every five of its mission-critical applications to IBM’s Bluemix cloud.

He claimed IBM had the edge as an enterprise-grade cloud provider because it offers "a complete set" of cloud server choices – bare metal, private and public VMs – all of which are certified under the Information Security Registered Assessors Program (IRAP) from the Australian Signals Directorate (ASD).

IBM announced its first local data centres for Softlayer in 2014; since then the Softlayer brand has taken a backseat to Bluemix as the focus of IBM's cloud strategy.

Sydney was one of four additional cloud data centres opened by IBM in the second quarter, taking its global footprint to 55 data centres in 19 countries worldwide.