Both countries had been competing to win the $2 billion contract for the Square Kilometer Array, an instrument that will be 50 times more sensitive than the most powerful existing radio telescopes, Britain's The Daily Telegraph reported Friday.
"We have decided on a dual site approach," SKA board Chairman John Womersley said at Amsterdam's Schiphol Airport following a meeting of the organization's members in the Dutch capital.
Engineers will connect antennas at Australia's core site at Mileura station 60 miles west of Meekathara in Western Australia to other antennas distributed across Australia and New Zealand, while South Africa's site in the arid Karoo region will be connected by a remote link to a network of dishes stretching across southern and eastern Africa and as far away as Ghana.
Construction is scheduled to start in 2016 and the SKA system is intended to be operational by 2024.
The SKA will be capable of scanning the sky 10,000 times faster than, and with 50 times the sensitivity of, any other telescope, officials said, and will aid in the study the origins of the universe.
It will be sensitive enough to detect weak signals that could indicate the presence of extraterrestrial life, they said.