New Zealand's richest person Graeme Hart added nearly $2 billion to his fortune in 2017, according to the latest Bloomberg Billionaires Index.

The owner of Auckland-based private equity firm Rank Group saw his net worth jump 21 per cent to NZ$11.03b in the year to December 28.

That's an increase of some $1.92b and makes him the 203rd richest person in the world, according to the index.

Rank Group's three main divisions are Reynolds Group, which owns food packaging and consumer products businesses, building materials supplier Carter Holt Harvey and vehicle parts business Automotive Group.

Hart, 62, was reported by Forbes magazine in March this year to be worth even more than Bloomberg's estimate, putting him at number 133 on its billionaires list with net worth of $13.5b.

It's been quite a journey for the man from Auckland, who dropped out of Mt Roskill Grammar aged 16 to become a panel beater.

He was one of only a few applicants to be admitted to the University of Otago's business school without first attaining an undergraduate degree, Bloomberg reported.

In his thesis, he wrote about finding cheap, easy-to-run, underperforming businesses with products that people use every day and using leveraged buyouts to acquire those assets.

Graeme and Robyn Hart. Photo / Norrie Montgomery

True to this approach, he bought and merged four party-hire companies in the mid 1980s, soon attaining a monopoly in the provision of goods and services for corporate events.

He sold for a profit and reinvested in a safety clothing business, at the same time founding his golden ticket, Rank Group.

Rank acquired 12 companies for a combined value of $19.7b between 2002 and 2012, according to data compiled by Bloomberg.

Rank's largest division, Reynolds, includes Graham Packaging, which services Coca-Cola, Pepsico, Kraft, Heinz, Procter & Gamble and Dopaco, which supplies McDonald's, Burger King and Wendy's fast food chains.

When he became New Zealand's first billionaire more than a decade ago, he told the Herald that dollars were a "byproduct" of what he does.

"Business is what gets me out of bed in the morning," he said in 2003. "That's my hobby".

Meanwhile, Amazon founder Jeff Bezos is now the world's richest man with a fortune of around $141b, knocking Microsoft's Bill Gates from the top spot, according to the Bloomberg index.

American tycoon Warren Buffett, of Berkshire Hathaway, was ranked the world's third richest man with $121b, Spanish magnate Amancio Ortega, founder of the Inditex fashion group, was fourth with $106b in the bank, and Facebook's Mark Zuckerberg fifth with $103b.