MEXICO CITY — To a Mexican ear, Angel Perez speaks Spanish like a foreigner. To an American, his English is pure Texas. His mother took him from Mexico to the United States when he was two years old and they settled in Graford, Texas, population 600. He graduated from high school there, got a job cutting cedar trees, met a young woman from a town nearby and had two kids. But last year, Perez, who didn’t have legal immigration papers, was deported. He found himself in Mexico City with close to nothing: His girlfriend and kids, his friends and his now-former job were all back in Texas.

Perez has a rugged, muscular build and is never without his red, Texas Rangers baseball cap. He cuts his hair in a Mohawk and wears a fake bullet as an earring through his left earlobe. Mexico City could not be more different from his rural home back in the States. And he spoke Spanish like a school kid. Perez searched for work, but there weren’t many options. He found a couple days of work moving furniture with a cousin for $15 a day. But after that ended, Perez didn’t know what he could do.

Then, a little more than a month after his arrival, Perez got a break. One afternoon, as he waited in a Mexican government office to apply for an official ID, a woman in line told him about a place called TeleTech. The company was hiring, she said — all he had to do was prove he could speak English.

The next day at the downtown TeleTech office, in a three-story building across the street from the Monument of the Revolution, Perez didn’t know what exactly he was applying for. “I’d never heard of TeleTech, and I didn’t know what it would be,” he recalls. “I just interviewed and they asked about my English.” It was not until he started work a few days later, that Perez learned what he’d been hired to do: talk by phone to people in the U.S. about their satellite TV service.

TeleTech, it turned out, is one of the leading global outsourcing firms. The three-decade-old Denver company is often described as a pioneer in outsourcing. By last year, it pulled in $1.2 billion in revenue from call centers in at least 24 countries. Mexico is a growth opportunity for TeleTech: It runs three call centers there and is planning to open a third in the city of Puebla.

Like the half dozen other major call centers in Mexico City, TeleTech works exclusively with U.S. corporations; it handles customer service and technical-assistance calls for clients such as Time Warner, Dish TV and Best Buy.