German submarine builder ThyssenKrupp Marine Systems says it can build 12 subs in Australia on time and for $20 billion or less.
The company insists its long experience as a designer and commercial submarine builder, with 161 boats constructed for 22 countries since 1960, make it a low risk for Australia - far lower than Japan whose Soryu-class submarines have never been exported.
"It is our core business to sell a submarine which our customer wants, build it in their country and transfer technology and know-how," a source close to the TKMS bid said on Wednesday.
The government is considering what submarine will replace the navy's six Collins boats that reach retirement age from 2026.
Labor's 2009 and 2013 Defence white papers propose 12 advanced new subs assembled in South Australia where the Collins boats were built.
The coalition has hedged on committing to an Australian build with a final decision tipped for the new Defence White Paper next year.
Two years ago, there were no foreign contenders able to meet Australia's requirements. But now there are several, from France, Germany, Sweden and Japan, whose Soryu-class boats are regarded as closest to Australia's specifications.
Some media reports suggest Soryu is a done deal, although it would still require substantial modification.
TKMS is proposing its Type-216, a 4000-tonne scaled up version of its widely used 1860-tonne Type-214. That gives it a range of 13,000 nautical miles and endurance of 80 days.
The Type-216 doesn't actually exist yet, although it's 80 per cent in the water. The company says it could produce the first boat in time for decommissioning of HMAS Farncomb in 12 years.
"That means getting a contract in the next year or two, in 2016 or thereabouts, but we can meet that schedule," the source said.
The $20 billion price tag is regarded as the ceiling and final costs could be less.
TKMS could build in either Germany or Australia. The company, which briefly owned Collins parent Kockums, is familiar with Australian facilities and shipbuilder ASC.
"Our position is simply we can build in Australia because we have a proven track record in places such as Greece and Turkey and Korea," the source said.