The vessel, which was built in 1986, was refurbished four years ago and has been bought from bankrupt German owner, Premicon Hochseekreuzfahrt.
CMV, which had been chartering the 21,000 tonne vessel, is reported to be in the final negotiations of the purchase agreement.
Astor will return to Australia for its 2015-16 season, which will be its third year based at Fremantle.
The season will include an Asian cruise from Fremantle to Hong Kong with stops in Singapore, Malaysia, Brunei, Sabah, Philippines, Vietnam and Indonesia.
Astor originally joined the CMV fleet in December 2013 under a charter with ship management services provided by CMV’s majority shareholder, Global Maritime Group, which has acquired the vessel.
Astor will operate under long-term charter to CMV.
Christian Verhounig, chief executive and chairman of CMV, said: “The acquisition of the Astor is another important milestone in the strategic development of the group’s presence in the international markets.
“Astor has a fine pedigree and provides an important smaller ship premium option within our cruise portfolio,”
CMV commercial director Chris Coates said: “Astor has added 22,000 passengers to our global carryings and since her introduction has proved a firm favourite with high levels of customer satisfaction and repeat business being achieved.
“Next year we have programmed a special eight-night ex-London Tilbury round Britain cruise before Astor starts her German market season and forward booking levels are very encouraging”.
Astor arrived in Fremantle on Saturday following a 38 night re-positioning voyage from Tilbury and will continue to operate cruises under the CMV brand for the Australian market during the southern hemisphere summer season.
The ship will then reposition to Europe in April 2015 to operate a summer season of ex-Kiel and Bremerhaven sailings for the German market under the TransOcean brand.