Silm's worth jumped $19 billion since the last survey in 2006, making it the greatest one-year gain by a billionaire in a decade. In addition to providing the country's leading phone and Internet service, his holdings also include a tobacco company and an airline.
"It's virtually cradle to grave. It's Slimlandia," said George Grayson, a Mexico expert at the College of William and Mary in Virginia. "You are engulfed by Slim in Mexico."