MacKenzie Bezos, who finalised her divorce from Amazon founder and chief executive Jeff Bezos this year, is pledging to give away half of her fortune to charity.
The novelist said on Tuesday that she signed The Giving Pledge, a campaign to have the ultra-wealthy pledge at least half of their fortunes to charitable causes
It was formed in 2010 by billionaire investor Warren Buffett, and Microsoft co-founder Bill Gates and his wife Melinda.
Those who join can give away their money while they are alive or leave instructions in their wills. They also decide where and how their money is donated.
In a letter Tuesday, Ms Bezos did not say how she planned to give her money away. The divorce left her with a 4 per cent stake worth more than $36 billion (Dh132.24bn) in the online shopping giant.
“I have a disproportionate amount of money to share,” she said in her letter.
Mr Bezos, who has not signed The Giving Pledge, tweeted his support.
“MacKenzie is going to be amazing and thoughtful and effective at philanthropy, and I’m proud of her," he said. "Her letter is so beautiful. Go get ’em, MacKenzie.”
The couple, who have four children, first announced that they were divorcing in January ahead of a National Enquirer story that revealed Mr Bezos was having an affair with a former TV host.
He later accused the tabloid’s publisher of threatening to publish explicit photos he sent to his lover unless he stopped investigating how the paper obtained the private messages.
The National Enquirer has denied the accusation.
Mr Bezos, who founded Amazon as an online bookstore more than two decades ago, has become the world’s richest man thanks to the company's surging stock price.
His stake in the company after the divorce is worth more than $108bn.
Mr Bezos has wrestled with how to give away some of his fortune, asking his Twitter followers in 2017 for philanthropic ideas.
Last year, he committed $2bn to a charitable fund that will focus on opening preschools in low-income neighborhoods and donates money to charities that help homeless families. So far, he has given $100 million to that fund.
Mr Bezos has also said that he considered his self-funded space exploration company Blue Origin and his purchase of The Washington Post newspaper as "contributing to society and civilisation".
On Tuesday, The Giving Pledge said that Ms Bezos was one of 19 new people or couples who joined the pledge, bringing the total number to 204.
Others who have signed the pledge include Elon Musk, co-founder of electric car company Tesla, and oil baron T Boone Pickens.
