CAMBRIDGE, England, Sept 15 (Reuters) - The chief executive of British commercial broadcaster ITV said ad markets remained uncertain despite a bounceback in spending by companies in recent months.

"There's definitely a bounceback, and it's very buoyant at the moment and that's been really fantastic, but I think there is quite an element of bounceback in there and I hope that will last," Carolyn McCall said at the Royal Television Society Convention in Cambridge on Wednesday.

She said ITV did not know how winter would pan out yet or what would happen next year.

"So I think there still remains uncertainty," she told an audience of TV executives.

"I'm fine with uncertainty because I think we have a robust business and we actually have a more resilient business now than we did when we went into lockdown and so I think we can absorb the uncertainty, we just have to keep moving ahead."

ITV said in July it expected ad revenue that month to be up 68%, August up 17% and September to be positive.

(Reporting by Paul Sandle; Editing by Kate Holton)