The band consisted of Cheryl, Nicola Roberts, Kimberley Walsh, Nadine Coyle and Sarah Harding.
The 63-year-old, who recently announced his return to the "X Factor", also made a dig at the girls, claiming Nadine was the only one that could sing, reported Digital Spy.
"I didn't give them a lot of my time but they didn't give me time and they didn't even like each other!" he said.
"It was problems from day one there. I contacted them as much as I could but they didn't like each other. It was never going to work because I said Nadine was the best singer and she was. She was the voice of Girls Aloud.