T-Mobile US has been working to make a new name for itself in the US market by offering unconventional smartphone plans so customers can upgrade whenever they want. The company might now be looking to expand its reach even further, perhaps with rival Sprint.

Speaking to Reuters, Braxton Carter, chief financial officer at T-Mobile, said: "It's the logical ultimate combination," when speaking about T-Mobile and Sprint together. Carter didn't come right out and say any talks between the two carriers had taken place, but it's definitely interesting to hear him theorise about it.

A potential merger between T-Mobile and Sprint could position the two companies to take on the larger US carriers, AT&T and Verizon, head on. The question is whether US regulators would approve the deal. The government already blocked the proposed sale of T-Mobile to AT&T in 2011, emphasising that it would create too much of a monopoly. It's not clear if the merging of two smaller carriers would produce the same results.

In a pursuit to add more customers, T-Mobile scooped up smaller regional carrier MetroPCS in April, adding nine million customers in one move. T-Mobile plans to shut down MetroPCS's network over two years and move everything into T-Mobile.

Right now, we'd file Carter's comments under pure speculation. He does propose consolidation would be better in the US - to create one strong third carrier, rather than four. "We think it's not a question of if but when that there's further consolidation in our industry," Carter said.

UK-carrier EE was formed in 2010 through the merger of T-Mobile and Orange. It appears something similar could happen in the US. A merger between T-Mobile and Sprint could also create quite a messy situation for customers. T-Mobile runs on a GSM network and Sprint runs on a CDMA network, not to mention how much the two carriers' plans differ from each other.

We've reached out to T-Mobile and Sprint in the hope of learning more.