Guernsey's States Assembly has passed three amended propositions to enable Sure to buy Airtel, but none was carried unanimously.
The votes, after hours of debate, allow for a temporary suspension of Guernsey's competition law, which is the mechanism needed to allow Sure to buy Airtel.
Deputy Neil Inder, whose Committee for Economic Development brought the policy letter, says the agreement will see significant investment in Guernsey's telecoms network:
"Sure will build a completely new mobile network that offers the latest generation of technology and services, to greatly enhance data speeds and improve coverage and call quality."
The deal facing deputies had already been signed off by Jersey's competition regulator. Consumer choice will continue, as the Co-Op will enter the telecoms market as a third operator.
But none of the propositions was carried unanimously. Deputy Yvonne Burford disagreed with the deal:
"Creating a virtual monopoly does not create a social benefit for consumers, quite the contrary."
As did deputy Steve Falla:
"It will be observed externally, and potentially impact on the perception of Guernsey in other jurisdictions, some of whom we are obliged, under international agreements, to co-operate with in matters touching on competition."
Sure's CEO Alistair Beak was thrilled with the result:
"We are grateful that deputies have recognised the numerous strategic, economic and social benefits of our acquisition of Airtel.
The approval paves the way for a significant investment of up to £48m in a world-class 5G mobile network for the islands. We have made several legally binding commitments to ensure Sure and Airtel customers, as well as the wider community, benefit significantly."

Number portability issue between Coop Mobile and JT resolved
Guernsey's emergency sleeping pods 'in demand'
Alderney one-step closer to getting a swimming pool
Tickets on sale for women's Muratti
Move to get a full size inflatable pool for Alderney
Three Guernsey seal pups released in spring sunshine
Work begins to clear fallen trees from Guernsey's Reservoir Walk
Guernsey Police to target drivers who put others in danger