The Australian Navy will allow shared accommodation for male and female sailors aboard its submarine fleet in a bid to attract more women to the silent service.

The move, announced yesterday by Defence Science and Personnel Minister Warren Snowdon, comes ahead of the Government's expected decision to open all combat roles to women.

It will be detailed to submariners and their families at a meeting next week at the fleet's base at HMAS Stirling, near Perth.

Women have served aboard the navy's six Collins class submarines since 1998, but only 44 of the 560 sailors crewing the boats are female. Until now women had to sleep in female-only six-berth cabins.

"A lack of dedicated bunk space on board has occasionally led to female submariners missing out on postings because of bunk limitations, which has, in turn, denied the submarine force qualified specialists," Snowdon said.

"These limitations have also meant that only two of our three operational submarines have been able to accommodate females."

He said trials conducted over several years across the submarine force with officers and senior sailors had been successful, and strict rules would be imposed to maintain the "dignity and privacy" of submariners.

Rules restricting women submariners to female-only berths not only potentially limited their careers, but also hindered the ability to recruit crews for a service that has had problems attracting crews.

The navy has led the way in opening doors for women. It has a larger proportion of women serving in its ranks - 18 per cent - than both the army and the air force, and most of its front-line jobs are open to females.

"It should be pointed out that 97 per cent of navy positions, including combat-related positions, are already open to females, but this latest measure is a significant step in the right direction," Snowdon said.

"At this stage, only clearance diving remains a restricted employment category."

Snowdon said the decision to adopt shared accommodation, with the first fully integrated junior sailor messes, beginning next month, was a major step forward for women in the Defence Force.

"It will ensure that our female submariners access the same training and career-progression opportunities as their male crewmates," he said.

"The Government believes it is important that the nation's defence forces be representative of the community it serves and it's committed to ensuring that female military personnel have opportunities for career progression and development."

Defence Minister Stephen Smith is expected to present a wider recommendation opening all but a few combat roles for women to the Cabinet soon.

DEFENCE DEALS INCLUDE NAVY CHOPPERS

Australia yesterday confirmed orders for new naval helicopters, a massive amphibious warfare ship and more armoured troop carriers in separate deals worth several billion dollars.

The largest order is for 24 Lockheed-Martin Seahawk combat helicopters, worth A$3 billion ($3.7 billion), to replace the earlier versions the navy has been flying since the late 1980s.

The Seahawk was chosen over the rival European NH90 NFH, operated by the army and the RNZAF, largely because of its use by the United States, Australia's major defence partner.

The new helicopters, which will enter service between 2014 and 2020, will fly anti-submarine missions from the navy's Anzac frigates and the three new air warfare destroyers now under construction.

Defence Minister Stephen Smith said the Seahawks would provide the navy with the attack capability that was to have been provided by the now-scrapped fleet of Seasprite helicopters.

The Seasprite was dumped after more than A$1 billion ($1.25 billion) was spent on unsuccessful upgrades.

Smith and Defence Materiel Minister Jason Clare also announced the finalisation of the A$100 million purchase of the former Royal Navy amphibious ship Largs Bay as a stopgap until its two new Canberra-class vessels enter service.

The Australian Navy was left without amphibious capability with the scrapping this year of one of its major vessels, HMAS Manoora, its sister ship Kanimbla in long-term maintenance, and new problems keeping the ageing heavy-lift Tobruk out of service.

Australia had been relying on HMNZS Canterbury to fill gaps.

Smith and Clare also announced the signing of a contract with Thales Australia for an additional 101 Bushmaster armoured vehicles at a cost of A$133 million.

The new troop carriers will be fitted with extra protection for use in Afghanistan.