AT&T has agreed to buy Nextel Mexico for $1.875 billion from NII Holdings. The deal, which excludes Nextel Mexico's outstanding debt (NII Holdings filed for bankruptcy in September), represents AT&T's second such acquisition in three months.

With Nextel Mexico, AT&T will inherit the company's spectrum licenses, retail locations, network assets and roughly three million customers. Nextel Mexico's network covers roughly 76 million citizens. AT&T is planning to merge Nextel Mexico with Iusacell.

Combined with its $2.5 billion acquisition of competing carrier Iusacell and its existing footprint in the US, AT&T now has the potential to reach more than 400 million consumers and businesses across the US and Mexico.

AT&T is no doubt interested in offering roaming solutions for travelers from both countries but the real driving factor behind these recent acquisitions is future growth. Specifically, AT&T is banking on Mexico following the US in terms of strong smartphone penetration and mobile data growth according to Wells Fargo Securities analyst Jennifer Fritzsche.

All of this recent spending - lest we forget that AT&T is also waiting to close on a $48.5 billion deal to purchase DirecTV and is in the middle of a heated battle with Verizon in the ongoing spectrum auction - could really stretch the company thin.

For its part, NII plans to use the money to help dig itself out of bankruptcy and fund its Brazilian unit.

AT&T expects to close on the deal by the middle of the year pending approval from regulators and the bankruptcy court.