GREAT FALLS, Mont. -

Cellular One is discontinuing its wireless service in Montana at the end of July while an AT&T authorized dealer from Utah is taking over the company's seven stores in Montana.
    
Cellular One CEO Jonathan Foxman notified customers earlier this month that the service was being continued because the company couldn't afford the cost of upgrading its Montana network to 4G technology. The letter said Cellular One customers would receive a $100 credit and pay no activation fees if they switched to AT&T. Early termination fees also would be waived.
    
Verizon and AT&T are Montana's largest wireless companies.
    
Spring Mobile spokeswoman Heather Bailey says the Utah-based company will be operating the Cellular One stores in Billings, Butte, Great Falls, Helena, Kalispell and Missoula. The stores have about 20 employees.