Vodafone is in "exploratory" talks to merge its Australian business with rival telco TPG Telecoms.
Broadband provider TPG surprised the market down-under last year when it paid A$1.3bn for spectrum to start its own mobile network.
Vodafone Australia, which is owned half and half by Hutchison Telecommunications and Vodafone, is the third biggest mobile operator in the country, behind Telstra and Optus.
Statements from both parties confirmed talks were ongoing, sending TPG shares 20 per cent up to a near two-year high.
TPG said: "There is no certainty that any transaction will eventuate or what the terms of a transaction would be," while Vodafone called the talks "non-binding".
The deal makes sense for TPG as it would be able to use Vodafone's existing infrastructure for its new network, and would not have to pay to build its own.
A deal would also give Vodafone access to new customers – rivals Telstra and Optus are also likely to benefit from the deal as competition in the market will not go up with an extra mobile operator.