Selfridges' billionaire owners, the Weston family, have launched a formal auction to sell the historic department store business.
It is understood that advisers at Credit Suisse will start looking for a buyer, with the company valued at as much as £4 billion.
They will send out information memoranda - documents used to pitch the target to potential bidders - to begin the process, which could be completed by the end of the year.
It was first reported last month that the retail business could be sold after an unnamed bidder approached the Westons - who own a majority stake in Primark owner Associated British Foods - with a move to buy Selfridges.
In 1908, Harry Gordon Selfridge invested £400,000 of his own money in opening a department store at the then-unfashionable west end of Oxford Street after visiting London from his native Wisconsin, in the USA.
Selfridges & Co went on to become a household name, with Selfridge chairing the company until he was ousted in 1941 after becoming obsessed with twin sisters who were dubbed the Cheeky Girls of their day.
Selfridges' billionaire owners, the Weston family, have launched a formal auction to sell the historic department store business
It is understood that advisers at Credit Suisse will start looking for a buyer, with the company valued at as much as £4 billion. Above: Galen Weston Jr (second from left) with his wife Alexandra Schmidt (left), mother Hilary and father Galen Weston Sr, who died in April this year
He was the focus of the popular ITV drama Mr Selfridge, in which he was portrayed by American actor Jeremy Piven.
The firm has been controlled by the Weston family since 2003.
It is understood that no formal bid has yet been tabled for the iconic shop, but a small number of parties have already expressed their potential interest.
The business runs 25 stores worldwide, including its flagship Oxford Street store and Birmingham site within the Bullring.
Selfridges has performed strongly in recent years, despite a wider downturn in the department store sector which has seen the collapse of Debenhams and declines at major rivals.
Meanwhile, Selfridges has seen a surge in profitability over the past decade as it has been boosted by heavy investment in stores.
Nevertheless, the group was hit by the enforced closure of sites during the pandemic.
A year ago, the company cut some 450 jobs, around 14 per cent of its total headcount, following the 'toughest year' in its history.
It will now face the significant challenge of weakened footfall and fewer tourists in key areas, such as Oxford Street.
When it opened, Selfridges was a shopping marvel unrivalled by other retailers.
In 1908, Harry Gordon Selfridge (pictured right with his daughter Rosalie) invested £400,000 of his own money in opening a department store at the then-unfashionable west end of Oxford Street after visiting London from his native Wisconsin, in the USA
The shop was an instant hit with Londoners. It is seen above on its opening day in March 1909. Crowds of men and women are seen waiting to get inside
The Oxford Street store boasted nine Otis lifts which took customers around more than 100 departments selling everything from swimsuits to fur coats.
The central aim was to give people comfort as they shopped.