SYDNEY, Australia — The lead singer of the hugely popular children's group The Wiggles announced Thursday he would stop performing because of illness.

In a video-recorded statement, Greg Page said he had been suffering a condition called orthostatic intolerance that had left him debilitated.

"It means that I'll no longer be able to sing and dance as I want to and as a result I've decided to stop performing with The Wiggles,'' said Page, 34, who is known for his bright yellow T-shirt.

The Wiggles were Australia's top-earning entertainers last year, ahead of No. 2 AC/DC and No. 3 Nicole Kidman. The four men in brightly colored T-shirts, accompanied by a cast of characters including Dorothy the Dinosaur and Wags the Dog, grossed US$39 million last year.

Page helped found The Wiggles in 1991 after he and two other members met while studying early childhood education at Sydney's Macquarie University.

The group has franchised its enormously popular recipe to several non-English speaking countries, including Taiwan.