OTTAWA — The federal Competition Bureau wants to stop Rogers from buying Shaw, on the grounds that the $26-billion acquisition would hurt the national wireless market.

Here’s what you need to know:

The objection: Although the proposed takeover includes TV and radio stations, home-phone, cable and internet services, the complaint from competition commissioner Matthew Boswell is strictly about the effects of combining Rogers’s and Shaw’s cellphone and wireless internet businesses.

Shaw has been “a strong, disruptive regional competitor” in Western Canada, the bureau said, increasing its accounts by 101 per cent since 2016—in a time when the Big Three (Rogers, Bell and Telus) added just nine per cent. Shaw, the No. 4 player, has been an aggressive fighter on price and service and has forced the Big Three to keep pace.

Boswell’s announcement made clear that to satisfy him, Rogers and Shaw need to sell their surplus wireless spectrum licences—for Shaw’s discount Freedom Mobile brand—to somebody who will be a real competitor, filling Shaw’s existing role in the cellphone market.

Is this a big deal? Innovation Minister François-Philippe Champagne had already said he’d use his ministerial authority to block the merger unless the combined company divested some of the wireless licences that Shaw would bring into the marriage. In a sense, this is just another regulatory power saying the same thing—it’s not a new objection striking out of the blue.

The Competition Tribunal, the specialized court-like body that hears the Competition Bureau’s case, could side with the companies.

But even if it does, just having the argument there means delaying the merger indefinitely.

What Rogers and Shaw say: The parties got a courtesy heads-up after markets closed Friday and released a statement a few hours later saying they’re committed to the deal. They “are engaged in a process to sell Freedom Mobile, with a view to addressing concerns raised by the commissioner of competition and ISED,” they said.

But they noted they’d agreed to extend their mutual deadline for closing the deal to July 31, beyond their oft-repeated target of the second quarter.

What the market says: Amid a broader market selloff, Rogers’s shares fell more than four per cent; Shaw’s fell more than seven per cent to $34.87. Rogers’s takeover bid is $40.50 a share.

What’s next: Rogers and Shaw said they’ll fight Boswell at the tribunal “while continuing to engage constructively with the Competition Bureau in an effort to bring this matter to a resolution.”

The bureau said the companies have 45 days to respond to its objection. Then it gets 14 days to reply to the response, and the tribunal makes the final decision on its own schedule.

In the meantime, Rogers and Shaw are reportedly talking with the private-equity firm that owns rural provider Xplornet, the Aquilini family (whose wide-ranging holdings include real estate, energy and agricultural enterprises) and Quebecor. Globalive has also been openly seeking to buy Shaw’s extra wireless licences.