Ang -- who is understood to be in the US finalising the details of his relocation -- had been managing the "entire scope of technology and development" at ninemsn, overseeing the program management, design, development and information technology teams, according to a biography provided by the company.
The CIO, who reported directly to ninemsn chief executive officer Martin Hoffman, also oversaw the company's data centre outsourcing operations.
His achievements included establishing business priorities focussing on revenue-generating projects and responsibility for production and services costing, as well as consolidation of ninemsn's publishing and content management platforms.
The biography pointed out that Ang had "worked directly with Microsoft in Redmond" throughout his five-year stint at ninemsn, a Microsoft-Publishing and Broadcasting Ltd joint venture.
A ninemsn spokesperson described Ang's move as "an attractive next step in Richard's career" given that blogging has emerged as one of the most popular uses of the Internet and users had created 25 million blogs on MSN Spaces since its beta debut on 2 December 2004.
She told ZDNet Australia it has turned to external recruiters for Ang's replacement, but couldn't provide more information regarding his new position.
Spaces has also attracted more than 75 million unique users worldwide and more than 1 billion page views each month. Its rivals include Google Blogger, SixApart TypePad and Yahoo 360.
Before joining ninemsn, Ang was the CIO at Integrated Research and worldwide software engineering manager at Unisys.
ZDNet Australia's Steven Deare contributed to this report.