Concert promoters Live Nation said Tuesday that the North American leg of U2's tour will be postponed until 2011.
Festival organizers said Bono called founder Michael Eavis to tell him. In a statement on Glastonbury's Web site, Eavis said it "was obvious from our telephone conversation that U2 are hugely disappointed."
A replacement headlining act has not been announced. The festival, which runs June 23-27, attracts more than 175,000 people.
Bono, whose real name is Paul Hewson, underwent emergency spine surgery Friday in Munich. He has been released from hospital but doctors recommend at least two months rest.