Twins David and Frederick Barclay, who also own The Telegraph newspaper and The Beaumont Hotel in Mayfair, bought the Ritz for £75m in 1995.
Now The Times reports that the brothers have appointed Richard Faber, Frederick’s former son-in-law, to advise them on a potential sale.
They are understood to have recently received serious approaches in the region of £800m, equivalent to around £6m per bedroom in the hotel.
Experts told The Times that buyers are likely to be from outside Europe. Qatar's Constellation Hotels bought out the Barclay’s majority stake in Maybourne Hotel Group, which is behind high-end London hotels Claridge’s, the Berkeley and the Connaught, in 2015.
The Ritz was originally opened by Swiss hotelier César Ritz in 1906.
Its restaurant was awarded a Michelin star in the 2017 edition of the red book.
BigHospitality has approached The Ritz for further comment.