Tanzania, Sept. 9 -- Michael Dell has overtaken Jeff Bezos in Forbes' billionaire rankings, becoming the world's third-wealthiest person for the first time after shares of Dell Technologies hit an all-time high, extending a six-month rally.

Dell's estimated net worth rose by $4.6 billion to $267.7 billion at Tuesday's market close, putting him ahead of Amazon co-founder Bezos, whose fortune fell by $1.4 billion to $265.2 billion after Amazon shares declined 0.6 percent.

Dell now trails only Alphabet co-founder Larry Page, whose estimated fortune stands at $277.9 billion, and Tesla and SpaceX chief Elon Musk, with $942 billion, according to Forbes' real-time billionaire ranking.

Shares of Dell Technologies rose 1.9 percent on Tuesday to...