François-Henri Pinault and Bernard Arnault will donate €300m between them to reconstruct the cathedral following the blaze.
Two of France’s richest men are to donate hundreds of millions of euros towards the rebuilding of Notre-Dame cathedral.
Shortly after François-Henri Pinault, who is married to the actress Salma Hayek, said he would be donating €100m (£86.4m), LVMH chief executive Bernard Arnault offered €200m (£173m) to reconstruct the “symbol of France”.
“The Arnault family and the LVMH group would like to show their solidarity at this time of national tragedy, and are joining up to help rebuild this extraordinary cathedral, which is a symbol of France, of its heritage and of French unity,” a statement said.
Earlier, Mr Pinault had been the first billionaire to say he would donate a large sum of money.
In a statement to French newspaper Le Figaro, he said he hoped the money would help to “completely rebuild Notre-Dame”.
Pinault is the chairman and chief executive of the Kering group, which owns such brands as Gucci, Yves Saint Laurent and Alexander McQueen. He is also president chairman of Artemis, the holding company that controls the assets of the Pinault family.
He is thought to be worth more than £19bn.
In the statement he said: “This tragedy strikes all the French and beyond all those who are attached to spiritual values. Faced with such a tragedy, everyone wants to revive this jewel of our heritage as quickly as possible.
“My father and I have decided to release from the funds of Artemis a sum of €100m to participate in the effort that will be necessary for the complete reconstruction of Notre-Dame.”
France’s Fondation du Patrimoine, a private organisation which works to protect French heritage, said it would be starting an international appeal.
It tweeted: “For Our Lady to be reborn from her ashes we are launching an international appeal. All donations received will be paid in full to the restoration site.”
The cost of rebuilding the cathedral is expected to run into the billions of euros.
At the time of the fire the 850-year-old building was undergoing a multi-million euro restoration project.
The cost of trying to maintain Notre-Dame has spiralled over the years and in the past the French government has looked to the private sector to help finance its upkeep.