Australia said Tuesday it had invited three companies from France, Germany and Spain to submit designs for its new submarine fleet -- a project expected to span the next 30 years.

Defence Minister Stephen Smith said Canberra had asked French naval defence firm DCNS, Spain's Navantia and HDW of Germany -- a ThyssenKrupp subsidiary -- to submit designs for the programme, which will see 12 new submarines built.

"The Future Submarine Project is a major national undertaking and is of a scale, complexity and duration never before experienced within (the) Defence (Department)," Smith said, adding that Australia would need a "significant amount of help from overseas".

"The submarines will be constructed over the course of the next three decades."

Jason Clare, minister for defence materiel, said the Future Submarines Project would involve hundreds of companies, thousands of workers and many skills that "do not currently exist in sufficient numbers".

"Some of those skills are available overseas, others will have to be grown here. Now is the time to develop a plan to make sure we have the skills we need when we start designing and building the submarines," he said.

Australia unveiled plans in 2009 to spend more than US$70 billion boosting its military capability over the next 20 years as global power shifts to the Asia Pacific.