Carlos Slim Helu is one of the world's richest men because he made the tough call: trying to gain control of Mexico's national phone company in 1990.

At that time, Slim already ran a small business empire, thanks to savvy acquisitions during Mexico's early-1980s downturn.

Mexico's economy was still struggling by 1990. At the World Bank's prodding, it planned to privatize dozens of state-run businesses, including Telmex, the phone firm.

With ties to President Carlos Salinas de Gortari, Slim had an inside track to make an offer for Telmex.

He partnered with America's SBC Communications and France Telecom to buy Telmex for $1.76 billion.

"Carlos was smart, hardworking and a visionary," said Edward Whitacre, now chairman and chief executive of AT&T and chief operating officer of SBC in 1990. SBC purchased AT&T in 2005.

Whitacre added: "(Slim) saw the potential in Telmex and had a long-term plan for unlocking that potential. The other thing I noticed was that Carlos also had a deep-seated concern about the welfare of his countrymen."

Once he had management control of Telmex, Slim improved operations at the badly run company. He upgraded equipment to modernize Telmex. He drove tough bargains with gear suppliers, says Jorge Pinto, Mexico's ambassador to Sweden from 1991 to 1994.

Slim pulled no punches with Sweden's Ericsson, the biggest gear supplier to Telmex, says Pinto, who's now a finance professor at Pace University in New York.

"He wasn't saying that he was going to throw Ericsson out of the market," said Pinto. "He was saying that he was going to look for the best (price) deal. He knew where to put money for profit."

Despite privatization, Mexico's phone rates have stayed high. Telmex still has 90% of Mexico's landline phone business.

Local and long-distance services fueled Telmex's profit. While secure, Slim diversified Telmex into Internet access and wireless services. In 1996, Slim purchased Prodigy, a distressed U.S.-based Internet service provider.

He expanded Telcel, Mexico's cell phone company, into America Movil. It has grown into Latin America's biggest wireless firm.

What does it all add up to?

In March, Forbes named Slim the world's second wealthiest man, with a fortune topping $53 billion, right behind Bill Gates.

Slim, 67, has practical views on sharing his money.

"Wealth is like an orchard," he told Reuters recently. "You have to share the fruit, not the trees."

Slim runs two charities, the Telmex Foundation and Grupo Carso Foundation, with endowments of more than $4 billion. At a March press conference to unveil a medical charity, Slim said:

"Our concept is more to accomplish and solve things, rather than giving, that is, not going around like Santa Claus."

He added: "Poverty isn't solved with donations."

Slim, the son of Lebanese immigrants, is a passionate Mexican nationalist. As is the custom in Spanish-speaking countries, he puts his father's surname first, followed by his mother's surname.

Slim's climb to megawealth is no rags-to-riches story. His father gave him a good financial start and key advice: hunt for bargains.

Slim's father was a teenager when he fled Lebanon, which was controlled by the Ottoman Turks. In 1902, Julian Slim arrived in Mexico.

Unrest soon gripped the nation. The Mexican Revolution began in 1910. It killed off one in every 15 people over the next decade.

Julian Slim took a gamble. In 1911, he opened a general store in Mexico City's central district. While many merchants fled the war-torn country, Julian Slim stayed. He purchased property at deep discounts in Mexico's Zocalo district as others eagerly sold.

Slim, born in 1940, learned from his father's boldness. He has said his father taught him to stand firm in tough times.

"When there is a crisis, that's when some are interested in getting out and that's when we are interested in getting in," Slim told Bloomberg Markets.

Slim made one of his key moves in the 1980s, during Mexico's debt crisis. As banks struggled and investors fled the stock market, Slim pounced. He snapped up Cigatam, a cigarette distributor, and Sanborns, a coffee and gift shop chain, at bargain prices.

One of six children, Slim gained his business acumen early on.

At 11, he invested in government savings bonds. He also kept a ledger to track investments and purchases. By 15, he owned shares in Mexico's largest bank.

In 1961, Slim earned a civil engineering degree.

He founded a stock brokerage in the mid-1960s and moved on into insurance. He regularly put in 14-hour workdays — and bottom-fished.

He regularly pored over company financial statements, analyzing strengths and weaknesses.

After gaining minority stakes at first, he would seek majority control of companies after gleaning their inner workings.

He focused on badly managed companies where he could turn things around by slashing overhead costs.

"We want as few management layers as possible, so that executives are close to the operations," he said.

In the '80s, Slim expanded into mining, real estate, construction, tires and paper goods.

His sprawling empire now includes a budget airline and a music retailer.

Slim has described his management style as practical. He runs a lean operation. There's no corporate staff at Grupo Carso.

For years, Slim worked out of a windowless basement in a drab, two-story building dwarfed by skyscrapers in the Lomas area of Mexico City.

While Slim has a flair for numbers, he's not a computer user.

Slim likes baseball because it's a game filled with statistics.

Slim's three sons run his businesses while he focuses on big strategy and projects, such as restoring Mexico City's historic center.

For Slim, business is a calling. His motivation has been an emotional need to succeed.

"When you leave your children a company, you are leaving them a big responsibility and a commitment," he told BusinessWeek. "You don't want to leave them with money; you want to leave them with a commitment."

BY REINHARDT KRAUSE