Concert promoter Evenko says people who bought tickets to this summer's performances by U2 will be offered refunds, but only when exact dates are announced for replacement shows.

U2 has been forced to postpone the North American leg of its upcoming tour, including two shows that were scheduled for the Montreal Hippodrome in July.

Those concerts will now be rescheduled for 2011, and Montreal promoter Evenko says tickets for the 2010 shows will be honoured.

Last week the band announced that frontman Bono had emergency back surgery after suffering an injury during rehearsal. Bono was released Tuesday from a hospital in Munich but doctors say he needs at least eight weeks of recovery time.

U2 tour producer/promoter Arthur Fogel is quoted on the band website: "Although we understand the disappointment to U2 fans, first and foremost comes the recovery of Bono."

A temporary stadium was going to be built at the Hippodrome site in Montreal to accommodate 80,000 people.