If you’ve ever been to Mexico, then Carlos Slim owes you a gracias. It’s almost impossible to go a day in this country without spending a peso in one of his business.

Slim is the third richest person in the world, behind Bill Gates and Warren Buffett, and his fortune is estimated to be equal to 5.5% of Mexico’s GDP. Among other businesses, he owns restaurants, retail stores, hospitals, utilities, properties and banks.

Slim also controls almost all of the telecom industry — fixed-line and wireless.

Since being spun out of Telmex, Mexico’s largest fixed-line and internet provider, in 2000, wireless telecom America Movil (NYSE: AMX) has been on a tear, up almost +500% in the past decade. The company pioneered the use of prepaid phones, which made cell phones financially viable for more Mexicans. America Movil controls about 70% of the Mexican wireless market. And Slim controls America Movil, with 54% of the outstanding shares.

Slim has turned Movil into the largest mobile operator — and the fourth largest company — in Latin America. Movil’s revenue has grown at an impressive rate of +55% annually from 2000 to 2008.

Aside from controlling the Mexican wireless telecom market, the company is expanding into other parts of Latin America. Movil is the largest mobile operator in Columbia, from where it derives 10% of its revenue.

Movil’s pricing power in Columbia and Mexico has allowed it to generate one of the highest operating margins in the industry, 27.4% — compared with 17.5% for AT&T (NYSE: T).

Movil’s fastest growing segment is its Brazilian operations. It is the second-largest cell phone operator in Brazil and derives 20% of its revenue from the rapidly emerging country. Movil added 2.1 million subscribers in Brazil in the fourth quarter ended December 31, 2009, a +14.6% increase year-over-year.

Movil’s operations in the Caribbean, Central America, Ecuador and Peru account for the balance of its Latin America revenue.

Movil has $400 million of cash on hand, money that can be used to expand its network across Latin America. It is one of the few wireless telecom companies to offer next-generation services across the region, which should attract customers over time. Movil’s contract with Apple Inc. (Nasdaq: AAPL) to sell iPhones in its Latin American operations should continue to drive new subscriptions.

#-ad_banner-#Movil’s fourth-quarter revenue jumped +13.1% to $8.2 billion, year-over-year. The company’s subscriber base increased +10% in 2009 and data revenue jumped +48.7%, compared with the year-ago period. Data plans enable phones to surf the Internet and use other advanced features.

Even the United States is part of Movil’s expansion. Tracfone Wireless, a unit of America Movil, is the fifth-largest U.S. mobile operator, and the number one provider of prepaid cell phones in the United States. In terms of subscribers, Tracfone is the second-fastest growing segment for America Movil.

Movil teamed up with Wal-Mart Stores, Inc. (NYSE: WMT) to distribute the Tracfone at Wal-Mart’s retail stores, in October 2009. Tracfone is the fastest growing prepaid phone provider, and the Wal-Mart deal will make the phone more accessible to potential customers. Movil added 1.2 million subscribers in the fourth quarter, bringing the U.S. total to 14.4 million.

Only one company is more dominant than America Movil in Mexico’s telecom market, and that company is Telmex. The company is practically a monopoly in Mexico, with about 80% market share of the fixed-line business. While Telmex operates in Mexico, its sister company, Telmex Internacional, operates in the rest of Latin America. Both companies offer internet, cable TV and fixed-line services.

And guess who controls these companies?

Telmex (Mexico: TELMEXL.MX) and Telmex Internacional (Mexico: TELINTL.MX) are controlled by Carlos Slim through Carso Global Telecom (Mexico: TELMEXL.MX), a holding company. Slim recently announced a plan to combine his telecom operations by purchasing Carso Global Telecom through America Movil.

America Movil plans to pay for the acquisition with its own shares. If the plan is approved by regulators, America Movil would indirectly acquire 59.4% of Telmex and 60.7% of Telmex Internacional.

In Mexico, the acquisition must be approved by Cofeco, the country’s telecom regulator. Slim said he does not plan to bundle services there, which should help Movil get the deal approved. The plan is expected to be more easily approved in Brazil and other South American countries.

The deal should improve profitability through cost-cutting synergies. It will also enable Movil to offer wireless, fixed-line, cable TV and internet services across Latin America and put it in a stronger competitive position against Spain’s Telefonica (NYSE: TEF), Movil’s primary rival in South America.

America Movil’s subscribers topped the 200 million mark in the fourth quarter, which compares with AT&T’s 85 million subscribers. It still has plenty of room to grow in Latin America, and the Carso Global Telecom deal could act as a catalyst to expand its subscriber base. Slim has a solid record of creating shareholder value, and that’s exactly what the acquisition should do in the long term.

The shares are trading at an earnings multiple of 14, an -18.7% discount to its five-year average multiple. This may be the best time for growth investors to pick up shares of America Movil at a discount.