The international consortium behind a plan to build the world's most powerful radio telescope on Wednesday signalled further delays in deciding whether it should be hosted by South Africa or Australia.

It was hoped that members of the SKA (Square Kilometre Array) Organisation would set a date for the eagerly awaited announcement during two meetings on Tuesday and Wednesday in the Netherlands.

But the organisation based in Manchester, northwest England, agreed only to set up a working group to examine further the two bids for the $2 billion (1.5 billion euro) project, which is due to report back next month.

"They noted that it is important to maximise the value from the investments made by both candidate host regions," it said in a statement.

"They therefore agreed to set up a small scientific working group to explore possible implementation options that would achieve this.

"This working group will report back to the members at a meeting in mid-May; its report will provide additional information to facilitate the site decision for SKA."

South Africa's Science Minister Naledi Pandor reacted with dismay at the postponement.

"I am disappointed at the delay. I hope that the SKA organisation will make a decision in the first half of 2012 and that the decision will reflect the best scientific outcome," she said in a statement.

Scientists hope the SKA, which will be 50 to 100 times more sensitive than today's most powerful radio telescopes, will shed new light on fundamental questions about the universe, including how it began and why it is expanding.