Organiser Reed MIDEM said it was postponing the event due to "growing concerns related to the coronavirus".
"The well-being of our clients and staff is our priority," said Reed MIDEM chief executive Paul Zilk."Given the evolving context, the best course of action is to postpone MIPIM to June."
The annual fair, which is attended by thousands of architects and property professionals, declared only yesterday that it would go ahead despite ongoing outbreaks of the Covid-19 strain of coronavirus in Europe.
Attendees cancelling trips
However, up to ten per cent of participants are thought to have pulled out of the event, citing fears of the virus. Architects including BDP, HOK and Austin-Smith:Lord are among those who withdrew from the event ahead of the postponement.
HOK cancelled its delegation on Thursday. "Due to the ongoing concerns with the spread of the Coronavirus, HOK's London Studio has decided to withdraw from #MIPIM2020," the firm's London office tweeted.
"HOK places a priority on the health and wellbeing of its staff hence this challenging decision, which sadly is affecting so many people and organisations."
BDP withdrew on Friday. "The health and safety of our employees is our top priority and we have taken the decision not to attend this year's MIPIM due to concerns regarding the spread of COVID-19 in Europe," BDP chief executive John McManus told Dezeen.
London architects Morrow+Lorraine also announced on Friday that they had cancelled their trip. "We felt it was inappropriate to risk exacerbating what is already a global emergency by making non-essential international travel," the studio said on Twitter.
"This is not a decision we have taken lightly," said MIPIM's Zilk. "We believe these new dates will provide the international MIPIM community with the opportunity to achieve their business objectives."
"We are grateful to our clients for their support and constructive input during this challenging period, and we look forward to talking with them in the coming days about MIPIM in June."
Virus impacting events around the world
France has seen a sharp rise in people testing positive for the virus this week, with Cannes reporting its first case on Thursday.
So far 73 people in France have been infected, with 16 new cases reported on Saturday. Shortly after MIPIM's announcement, the French government announced a temporary ban on public gatherings of more than 5,000 people.
The postponement of MIPIM comes after Milan's Salone del Mobile decided to shift from April to June following the coronavirus outbreak in Italy.
Other international events that have been cancelled or postponed due to the virus include the Geneva Motor Show, Mobile World Congress in Barcelona, the ITB travel fair in Berlin, Light + Building in Frankfurt and Design Shanghai in China.
MIPIM, considered the world's most important property fair, was expecting 23,000 attendees this year, including 1,500 architects. Speakers booked for the fair's conference included former French president Nicolas Sarkozy, designer Philippe Starck and Apple co-founder Steve Wozniak.