Microsoft Corp. Chairman Bill Gates regained the title of world’s richest person on Forbes magazine’s annual ranking of billionaires worldwide, as the global recession slashed the size of the list by 30 percent.

The number of billionaires fell to 793 from 1,125 last year. It was the first time since 2003 that the number of people on the list decreased, and the biggest drop since the magazine began the ranking 23 years ago.

The total net worth of the list fell to $2.4 trillion from $4.4 trillion last year, with the average billionaire worth $3 billion, down from $3.9 billion. The three wealthiest — Gates, Berkshire Hathaway Inc. Chairman Warren Buffett and Mexican telecommunications magnate Carlos Slim Helu — lost a combined $68 billion in the past year.

“The global economy’s being battered by a financial hurricane that has wrought devastating damage on the world’s financial systems,” Forbes Inc. Chief Executive Officer Steve Forbes said in a press conference in Manhattan today. “It’s no surprise that billionaires have been battered along with the global economy.”