NEW YORK (

TheStreet

) -- The richest man in the world is buying into

BlackRock

(BLK) - Get Report

.

Carlos Slim

, the Mexican entrepreneur-turned-mogul, has acquired shares in BlackRock, according to news reports, though it's not clear how much he holds. A spokesman for the company told

Bloomberg

that Slim's stake is less than the 2% figure reported by the

Financial Times

last weekend. That represents less than $635 million, based on Blackrock's current market cap.

Slim is the richest person on Earth, with $53.5 billion in wealth, according to

Forbes'

latest rankings. That tops second-runner-up and former

Microsoft

(MSFT) - Get Report

head

Bill Gates

by $500 million and No. 3,

Berkshire Hathaway's

( BRK-B)

Warren Buffett

by $6.5 billion.

Slim made his fortune largely by holding a near-monopoly on Mexico's cell phone market via his company America Movil. He also controls Grupo Financiero Inbursa, a large Mexican bank.

In recent years, Slim has also made some high-profile investments in U.S. companies. He offered a $250 million loan to the

New York Times

(NYT) - Get Report

during the crisis that came with a high interest rate and an equity provision giving him a 7% ownership stake. The move led to speculation over whether he'd take over the newspaper giant, which both he and the Times have denied. Slim also acquired a nearly 18% stake of high-end retailer

Saks

(SKS)

.

News of Slim's investment wasn't helping BlackRock shares on Monday: The stock lost as much as 1.4% in a broad market sell-off before recovering a bit before the close. By 4 p.m., BlackRock was down 17 cents at $168.98.

-- Written by Lauren Tara LaCapra in New York

.

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Lauren Tara LaCapra

.

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