Dallas, Texas - AT&T closed its $2.5 billion acquisition of Mexican wireless provider Iusacell from Grupo Salinas, the Dallas telecommunications giant said in a press release last Friday.

The acquisition gives AT&T ownership of Iusacell's wireless properties, which include licenses, network assets, retail stores, and about 9.2 million subscribers.

Iusacell's network covers about 70 percent of Mexico's 120 million citizens.

The acquisition helps AT&T with its plans to create the first North American mobile service area, which would cover consumers and businesses in the US and Mexico. The company is planning to increase smartphone adoption and mobile Internet usage in Mexico, where smartphone penetration is about half that of the US.

The acquisition has already yielded one benefit. AT&T announced this week that it would begin offering unlimited calls to any number in Mexico as part of its "World Connect Value" plan. The program costs $5 a month. Previously, AT&T charged 1 cent a minute for wireless or landline calls.

The unlimited calling is a boon to customers in the US who routinely make calls to friends and family in Mexico, potentially shaving off a significant chunk of the monthly international phone costs.

"Mexico is the most frequently dialed country among our wireless customers - and now they can call as much as they want with our enhanced World Connect Value package," said David Christopher, chief marketing officer of AT&T Mobility.

AT&T revised its World Connect Value package in December, increasing the rates to South American and Caribbean countries to anywhere from 5-to-20 cents a minute, depending on the country. The increases goes into effect after January 31st.

Calls to Canada under the program remain at 1 cent per minute.

Iusacell will continue to be headquartered in Mexico City, which will also be home to an AT&T team that will oversee the integration effort.