NEW YORK -- Forbes magazine says Amazon CEO Jeff Bezos briefly became the world's richest man Thursday, as stock in his e-commerce company hit an all-time high.

Microsoft founder Bill Gates reclaimed the lead by afternoon, as Amazon's stock fell below the day's opening price.

Still, Amazon has been trading at a record high. Its shares hit US$1,083.31 at about noon Thursday. According to securities filings, Bezos owns about 80 million shares, or 17 per cent; those shares were valued at more than US$87 billion at the peak. Bezos also owns The Washington Post through a holding company.

Forbes says Bezos' net worth was about US$90.6 billion when the market opened Thursday. Gates had US$90.1 billion.