MacKenzie and Jeff Bezos are divorced after 25 years of marriage, after a Seattle judge in the US signed an order on Friday formalising the separation. In April, Amazon, the world's biggest online retailer, said in a filing that 4 per cent of its outstanding stock or 19.7 million shares would be registered in MacKenzie Bezos' name after court approval of the divorce. The couple announced their plan to divorce in a joint Twitter statement in January, causing some to worry that Jeff Bezos could wind up with reduced Amazon voting power or that he and his then wife would liquidate a large position. The 4 per cent holding is valued at $38.3 billion, enough to place Ms Bezos 22nd on the Bloomberg Billionaires Index, a ranking of the world’s 500 richest people. Her former husband, retains a 12 per cent stake worth $114.8bn and remains the world’s wealthiest person. Ms Bezos has said she would give him voting control of her shares. She pledged in May to give half her fortune to charity to join the Giving Pledge, a campaign announced by billionaire Warren Buffett and Microsoft co-founder Bill Gates in 2010. The court papers formalising the divorce revealed little else about the terms of the separation. The couple filed a parenting plan for their children earlier this week. Ms Bezos, a 49-year-old novelist, said in an April tweet that she gave Jeff Bezos, 55, all of her interests in the <em>Washington Post </em>and space-exploration company Blue Origin. In a statement posted on Twitter in April, Ms Bezos said she was grateful to have dissolved her marriage with her former spouse "with support from each other". The personal life of Mr Bezos was thrust into the spotlight with the announcement in January that he and his wife were divorcing after 25 years of marriage and the revelation by the <em>National Enquirer</em> that he had been having an affair with a former news anchor. The couple married in 1993 and have four children. Jeff Bezos founded Amazon in their Seattle garage in 1994 and turned it into a colossus that dominates online retail.