It’s been a few months since AT&T announced its plans to acquire Nextel Mexico, but the $1.875 billion acquisition wasn’t official until last night. This marks the American company’s second acquisition of a major Mexican wireless carrier, the first being Iusacell, which AT&T acquired for $2.5 billion. AT&T plans to integrate the two carriers into a single company, which will lead AT&T’s expansion into Latin America’s second-largest economy.