The couple, who met in 2005 and have two children together, announced the decision in a joint statement.
The Russian billionaire and owner of Chelsea football club, Roman Abramovich, is splitting from his wife, Dasha Zhukova, the couple have announced.
Abramovich and Zhukova, an art collector and gallery director, met in 2005 and have two children together.
“After 10 years together, the two of us have made the difficult decision to separate, but we remain close friends, parents, and partners in the projects we developed together,” said a joint statement on Monday.
A spokesman for Abramovich, 50, declined to comment further, or to say whether the couple planned a formal divorce.
Forbes estimated Abramovich’s wealth at $9.2bn (£7bn) this year, making him the 139th richest person in the world. He is known for his love of luxury, owning the world’s second-largest yacht and a portfolio of property across the world.
Zhukova, 36, is the daughter of a Russian oil magnate, and was educated in the US. She was treated with some scepticism when she entered the international art world, opening her Garage gallery in Moscow in 2008 and famously declining to name a single artist she admired in an interview.
She courted controversy in 2014 and attracted allegations of racism after posing for a photograph sitting on a chair made from a mannequin of a black woman. She denied any racist intent and said the photograph had been taken out of context.
Zhukova has become a fixture on the international art scene, where rich Russians inject millions into the contemporary art market. Garage, in Moscow’s redesigned Gorky Park, has become one of the best museums in the Russian capital, featuring frequently changing exhibits and cultural events.
The couple’s joint statement said they “are committed to jointly raising our two children” and will continue to work together on joint projects, including Garage, and New Holland in St Petersburg, a formerly derelict and shuttered island in the centre of the city. Abramovich has poured millions of dollars into New Holland, to turn it into a social and cultural space. The oligarch often contributes to government-backed projects, a requirement for billionaires who want to stay on the good side of the Kremlin.
Zhukova is the third wife of Abramovich. He announced a divorce settlement with his second wife, Irina, in 2007, amid reports of the blossoming relationship with Zhukova. The payout was $300m, Russia’s Vedomosti reported at the time, a small fraction of Abramovich’s wealth. The couple divorced in Russia; had they divorced in Britain the settlement may have been much larger. The couple met in 1990, when Irina was an Aeroflot flight attendant. They have five children.
Abramovich is fiercely private and rarely gives interviews. For some years, it was a mystery whether he and Zhukova were married, but she confirmed in an interview in 2015 that they had married a few years after meeting.