The Commerce Commission has pushed back a decision on whether it will let Vodafone take over TelstraClear by more than a month to October 23.
The regulator had initially intended to release its ruling on the $840 million takeover bid today, but it is common for the commission to delay such decisions, often at the last minute.
Most analysts expect the commission will approve the takeover, when it releases its decision, but possibly with some conditions, which could include forcing the merged firm to dispose of more of its radio spectrum.
Vodafone spokeswoman Michelle Baguley said Vodafone was not proposing to buy all of the spectrum currently owned by TelstraClear.
TelstraClear's Australian parent Telstra would retain some spectrum in the 1800MHz and 2100MHz bands that could be used for mobile telephony, she said.
"Vodafone's acquisition of spectrum will not affect the ability of other mobile providers to compete and will ensure that Vodafone will remain within established regulatory caps. Indeed Vodafone expects that Telstra will offer retained radio spectrum for sale which will allow other providers to increase their spectrum holdings," she said