Mexico City -- Has Bill Gates been knocked off the world's pinnacle of wealth?

Mexican tycoon Carlos Slim is seen during the Reuters Latin America Summit in Mexico City in this March 22, 2007 file photo. [Reuters]

A respected journalist who operates a financial-news Web site in Mexico says it's quite possible.

According to Eduardo Garcia's latest calculations, which first appeared Monday on his Sentido Comun ("Common Sense") site, Mexican business magnate Carlos Slim climbed into the No. 1 spot with a fortune of US$67.8 billion at the end of the second quarter of 2007.

Meanwhile, Microsoft Corp. founder Gates has an estimated wealth of some US$59 billion, Garcia said.

Slim controls Mexico's largest fixed-line telephone company, Telefonos de Mexico, or Telmex, and owns other businesses in sectors from construction and music to restaurants and cigarettes. Garcia says Slim's current wealth represents nearly 8 percent of Mexico's total Gross Domestic Product.

In April, Forbes magazine reported that Slim had overtaken US investor Warren Buffett to become the world's second-richest person, with holdings of US$53 billion.

But according to Garcia, Slim took over the No. 1 spot as early as late March, with a fortune surpassing Gates' by about US$1 billion.

Garcia attributed Slim's latest rise to a 26.5 percent second-quarter bump in share prices for America Movil SA, the largest wireless service provider in Latin America, which Slim controls. Garcia's estimate of Gates' latest worth is based on a 5.7 percent rise in Microsoft shares during the same period.

Garcia acknowledged that his second-quarter calculations do not include possible gains in Gates' holdings outside of Microsoft, which according to Forbes represent more than half of the software mogul's fortune. He also noted that he does not take into account Slim's holdings outside of his numerous companies.

"I say that Slim is No. 1 because I have the latest figures of Forbes," Garcia said. "When Forbes revises their numbers, OK, then we'll have to wait and see."

In a statement Tuesday, Forbes did not comment on Garcia's calculations but said its next valuation of Gates' wealth will appear in September, in the annual Forbes 400 list of the richest Americans. A calculation of Slim's worth will be published next March, the magazine said.

Slim spokesman Arturo Elias Ayub said that Slim does not pay much attention to such lists.

"As he has said many times himself, he is not in any competition," Ayub said. "He is dedicated to working in philanthropy and creating jobs in Latin America ... and the truth is he is not in a race to see who wins first or 10th or 15th place."