Australia and New Zealand could jointly operate a new amphibious landing ship under a plan in which the elderly landing ship HMAS Manoora is replaced by a UK vessel.
Australia's amphibious vessels have often been used for regional disaster relief missions in conjunction with New Zealand.
Defence Minister Stephen Smith said he would discuss with his NZ counterpart the option of both nations jointly operating a new vessel.
HMAS Manoora and HMAS Kanimbla, both constructed in the US in the early 1970s and acquired by Australia in 1994, have been tied up in Sydney since late 2010 after a series of maintenance and seaworthiness problems.
Mr Smith said it had been planned to continue using Manoora, Kanimbla and HMAS Tobruk until the arrival of two new landing helicopter dock ships, both now under construction in Spain and set to enter service about 2015.
But on Friday, the minister received and accepted advice that Manoora should be decommissioned.
"The Kanimbla also requires substantial remediation work," he told reporters in Canberra on Tuesday.
It was not expected that Kanimbla would return to operational activity until at least the middle of 2012."
An inspection of Manoora revealed it required repair of significant hull corrosion and the replacement of both engine gear boxes.
It would take until April 2012 and $20 million to remedy.
Manoora, in any case, was scheduled for decommission at the end of 2012.
"That is not value for money for another nine months of service," Mr Smith said, adding he had asked navy and defence to come up with a comprehensive plan to transition to the two new landing helicopter dock ships.
Part of the plan was the prospect of either leasing or buying a 16,000-tonne Royal Navy Bay class landing ship dock, deemed surplus under the UK strategic plan, announced late in 2010.
That was discussed with UK Defence Secretary Liam Fox at the AUKMIN (Australia United Kingdom Ministerial) meeting in January.
"I am proposing to have a further conversation with secretary Fox in the course of this week," Mr Smith said.
"We are looking at other options including the possibility, for example, for shared or cooperative service with close countries and allies."