Five months after denying "incorrect and hurtful" reports of an imminent split, Russia's richest man and Chelsea owner Roman Abramovich, has confirmed his 16-year marriage to wife Irina is over.

In what may be one of the most costly divorces in history, the pair issued a statement saying Abramovich's corporate interests -- which include the Chelsea Football Club -- would not however be affected.

"Mr and Mrs Abramovich have divorced in Russia on a consensual basis and have agreed terms in respect of arrangements for their [five] children and a financial settlement," the statement said, without giving any details.

The divorce follows newspaper reports that Abramovich has been seen with a young Russian model, Daria Zhukova.

Newspapers, many of which ran the story on their front pages, said Irina Abramovich could get as much as half of her husband's estimated $18.7 billion fortune and said it was the biggest divorce settlement in the world.

Experts on divorce law said a 50/50 split of wealth accrued during the marriage would be normal procedure in Russia.

"Russian divorce law is pretty straightforward. You must equally split all property and assets which have been amassed since you have been married," said a lawyer at a major Western legal firm in Moscow.

But a source who worked with Abramovich for several years said Irina Abramovich is unlikely to get 50 percent.

"I'm pretty sure it is not going to be a 50/50 percent split. She will simply get some money, but whether it will be dozens of millions, hundreds of millions or billions -- that's something that only a very small group of people will know," the source said.

Abramovich, an orphan, split from his first wife, Olga, in 1990 and married Irina in 1991.

 The 40-year-old, who built up his fortune mostly from oil and aluminium businesses during the chaos that followed the fall of the Soviet Union, has become the poster boy for Russia's oligarchs, known for savvy business deals and sumptuous living.

Listed by Forbes magazine as the world's 16th richest person he is a source of fascination for the tabloid newspapers, who regularly splash photos of him and his former wife.

The tycoon, who is notoriously shy of the media, denied a newspaper report last October that his wife had been talking to divorce lawyers amid reports of her husband's close friendship with Zhukova, 25.

Abramovich's spokesman described the reports at the time as "incorrect and hurtful" and said suggestions the Abramovich family were facing serious difficulties were "similarly untrue".

The divorce news broke too late for Russian newspapers, but Moscow radio stations and websites had it as the top story on Wednesday.

Some websites showed pictures of Abramovich next to Zhukova, saying the strikingly beautiful daughter of an oil magnate and former girl-friend of Russian tennis star Marat Safin has been the main reason for Abramovich's divorce.