Cable & Wireless Optus will not release its Part A statement to bid for AAPT until Monday, May 31, the Australian Competition and Consumer Commission (ACCC) said on Friday.
C&W Optus on Friday offered to provide the ACCC with an undertaking that it will not proceed with the release.
According to officials, the ACCC is investigating the takeover bid, which would see Australia's second largest telecommunications carrier acquire the third largest.
Officials said the ACCC is concerned about the likely effect of the proposal on competition within the industry.
C&W Optus made its $5 per share cash offer for AAPT in mid-April.