The regulator in charge of ensuring a fair level of competition for consumers has given its approval for Telus to take over its much smaller cellular rival, Public Mobile.

The Competition Bureau of Canada has issued what's known as a "no action letter" for the transaction, after determining that it "is unlikely to substantially lessen or prevent competition in the sale of mobile wireless telecommunications services in Southern Ontario and Greater Montreal."

Those are the two main markets for Public Mobile, which came about after the last wireless spectrum auction in 2008 as an alternative to the Big 3 telecom incumbents of Bell, Rogers and Telus. Public Mobile primarily caters to the lower end, pre-paid part of the market. Telus signed a deal to buy Public Mobile and its 280,000 customers earlier this year.

$19 unlimited talk deal to end

During the bureau's review, it learned that Public Mobile was going to discontinue its $19/month "Unlimited Talk" plan due to financial sustainability issues. The bureau had concerns that the Telus sale might alter the timing of those plans, but in the release the bureau said it was satisfied by Telus's pledge to keep that deal going until the end of 2014 at least, something Public Mobile had promised.

Industry Minister James Moore already signed off on the deal earlier this month, making permission from the Competition Bureau the last major regulatory stumbling block that had to be crossed.

Public Mobile customers will be rolled into Telus's existing coverage map soon, both companies say.