Demand was high for tickets
AEG Live, the organiser of Michael Jackson's concerts at the O2 arena, could lose millions from the cancellation of the concerts.
Mr Jackson had been due to perform 50 dates at the London venue.
AEG said full ticket refund information would be released early next week for all Michael Jackson "This Is It" shows.
AEG has advised fans to hold onto their ticket vouchers and proof of purchase. It remains unclear what insurance cover AEG Live has.
As well as fans, thousands of casual staff set to work at the concerts will also lose out from the cancellation.
"On behalf of the entire AEG organisation we extend our deepest condolences to Michael Jackson's family and friends during this tragic time" said AEG in a statement.
Around 800,000 people bought tickets to see the pop star for concerts due to start on 13 July.
More than $85m (£52m) worth of tickets have been sold and AEG has spent $30m on the production already, according to a report in Billboard, the American music magazine.
One of the world's largest concert promoters
Has arranged tours for Justin Timberlake, Christina Aguilera, Bon Jovi and Prince
Owns dozens of venues in the US as well as London's O2 and a stadium in Berlin
Reports suggest that AEG, which also owns the complex formerly known as the Millennium Dome, has only insured the first 10 nights of the 50-date concerts.
It had proved difficult to get cover as insurers were unconvinced that Mr Jackson would be fit enough to perform all the dates.
Earlier this year, AEG Live's head Randy Phillips told newspapers that it was prepared "to self-insure to make up the dates". He later told Billboard that the company was well insured.
On Friday, Lloyds of London said: "We can confirm that some of the insurance for the Michael Jackson concerts are placed with Lloyds market but any losses [are] not likely to be significant."
Concert promoters have said it could be difficult to find a replacement artist for a venue that big for 50 dates.
About 1,000 staff are employed for each show, most of them on casual or temporary contracts. These staff would have been booked for the 50 shows already and will now need to be cancelled, a GMB union officer said.
AEG Live owns concert venues around the world and is a subsidiary of Anschutz Entertainment Group.