AT&T’s game-changing $39 billion deal to buy T-Mobile, creating the largest wireless carrier in the U.S., may be all about plans for the iPhone 4G in 2012, according to the Fast Company website.

The deal combining the country’s second-largest and fourth-largest mobile carriers will come under heavy scrutiny by federal regulators, and is expected to bring cost-cutting moves, including job losses, The Wall Street Journal reported.

The just-announced deal is stirring up plenty of buzz in tech circles. According to Fast Company: “Very soon after the news arrived, there was hot speculation that the deal was largely prompted by Apple’s iPhone 4, and specifically by AT&T’s desire to boost its network to compete with the new Verizon iPhone 4. This of course would enable many millions more U.S. consumers (folks tied to T-Mobile, or who prefer that network) to buy Apple’s wonderphone. Those hopes were quickly quashed when T-Mobile said it will remain independent, albeit under AT&T’s stewardship, for around a year, and it won’t offer the iPhone to its customers in that time.”

But the story notes that the combination of AT&T and T-Mobile creates “a new monster company that would be the biggest by far–beating Verizon’s approximately 300 million users by a large margin. And while AT&T and Verizon are busy pushing forward on its 4G long-term evolution upgrade to bring about the next generation of mobile data phones, T-Mobile actually has the largest existing 4G infrastructure in the US. By buying into T-Mobile, AT&T is setting itself up to take the lead in the race to 4G coverage.”