Australia and New Zealand have joined forces to bid for a multi-billion dollar international radio telescope.

New Zealand's Economic Development Minister Gerry Brownlee and Australia's Minister for Innovation, Industry, Science and Research, Senator Kim Carr, signed the agreement today in Sydney.

The signing is seen as a boost to Australia, which is competing with South Africa to host the Square Kilometre Array (SKA).

"Signing the arrangement sends a strong signal to the international community that both countries are committed to supporting SKA-related industry opportunities and promoting the relevant capabilities of Australian and New Zealand industry," says Brownlee.

Senator Carr says the SKA is one of the world's great science projects, comparing it to the Large Hadron Collider in Europe.

"New Zealand is crucial to building the global collaboration required for the SKA to reach its full potential," says Carr.

"If our bid is successful, the SKA will not only significantly increase Australia's and New Zealand's scientific capabilities; it will result in economic benefits and spinoffs in a number of areas, including supercomputing, data transmission, renewable energy, construction and manufacturing."

Spiral network

The SKA will comprise up to 5000 small radio antennas, all operating as one giant telescope.

Most will be concentrated in outback Western Australia, along with a series of remote 'array stations' positioned in a spiral configuration radiating out over thousands of kilometres.

The addition of array stations in New Zealand will see the baseline of the SKA extend from 3000 to 5000 kilometres. This will result in an almost doubling of the telescope's resolution.

"The scale is enormous," says Brownlee. "It is a truly mega science project, which has a discovery potential ten thousand times greater than existing instruments."

Professor Sergei Gulyaev of Auckland University of Technology says their close working relationship with Australian radio astronomers has helped them become part of the SKA bid.

"Without our Australian colleagues, we could never have made the leap to this next generation digital radio telescope," he says.

Australian-born astronomer Dr Melanie Johnston-Hollitt of Victoria University of Wellington says New Zealand has a lot to offer the Australian bid.

"New Zealand also has strengths in high performance computing, imaging, signal pipeline processing, engineering and antenna design," she says.

The announcement of the SKA's location is expected to be made in 2012.