Ansett-ANA/Ansett Airlines of Australia operated 12 DC-9-31s registered VH
-CZA thru VH
-CZL. The first arrived in March 1967 and the last was retired in August 1982.
Trans Australia Airlines/Australian Airlines operated 12 DC-9-31s registered VH
-TJJ thru VH
-TJU. The first arrived in March 1967, arriving minutes before Ansett-ANA's first machine by the toss of a coin, and the last was retired in November 1989.
Southern Cross Airlines, trading as Compass Airlines, operated 5 DC-9-82/83s (MD-80s) registered VH
-LNH thru VH
-LNL. The first arrived in July 1992 and they all operated until the airline collapsed in March 1993.
Mayne Nickless/IPEC Aviation operated DC-9-33F VH
-IPC and DC-9-33CF VH
-IPF. IPF arrived in August 1982 and IPC in January 1990. Both were sold to Independent Air Freighters as Jetblast 737 has mentioned above.
Further details can be seen at http://dbromage.railpage.org.au/aviation/ex-vh/DC9.html