The two merged companies have been valued at more than $3 billion, creating the fourth biggest vertically aligned telco in the Australian market and third in New Zealand.
ACCC said the two companies had limited overlaps in the supply of retail and wholesale fixed broadband, voice, transmission and data centre services.
In markets where the two do overlap, they focus on different customer segments, with M2 mainly focused on residential and small business customers, and Vocus on large enterprise and government customers.
The ACCC said the acquisition will not significantly increase vertical integration between wholesale and retail telecommunications services providers.
“Significantly, the merged firm will face significant competition from Optus, Telstra and TPG. This merger consolidates the fourth player in the market,” ACCC Chairman, Rod Sims, said.