Telecom magnate Carlos Slim has passed American billionaires Warren Buffet and Bill Gates to earn the top spot on Forbes' World Richest list.

Never before has someone from the developing world earned the spot, but Slim's son-in-law says he is not breaking out the champagne.

Arturo Elias Ayub says “this is a number brought out by a magazine that doesn't concern us, or worry us.” But he calls the designation a sign of “confidence in Mexico.” Slim is known for wearing inexpensive suits and rarely using the computers his companies sell.