Veteran broadcaster Sir David Attenborough has undergone surgery to insert a pacemaker.

A spokesman for the 87-year-old leading world naturalist, who was forced to cancel a speaking tour of Australia because of the ''urgent'' procedure, said doctors believed that the TV star was doing well.

Requires a pacemaker: David Attenborough.

''Sir David has now had the operation and his doctors are satisfied with his progress,'' he said.

News of the procedure came Tuesday afternoon, as it was announced his sell-out tour, which was due to start in Brisbane next week, had been cancelled.