ITV, the UK broadcaster known for the soap opera Coronation Street, forecast fourth-quarter revenue from advertising will drop 7 per cent as companies have become more careful over political and economic uncertainty since the country's June vote to leave the European Union.

Full-year ad revenue is expected to be down 3 per cent, though ITV expects to outperform the market this year and next, the London-based company said in a statement Thursday.

ITV provided the forecast as it reported nine-month financial results, including a 4 per cent drop in ad revenue in the third quarter.

"Over recent weeks, I think you can see the political and economic uncertainty has increased, particularly with the debate over a hard or soft Brexit," ITV chief executive Adam Crozier said on a conference call.

Advertisers are becoming more cautious, but the rate of decline in advertising is expected to ease, he said. “There’s no real change in behaviour, genuinely no cancelling of any campaigns.”

Analysts have warned ITV would suffer from any decline in TV ad spending over uncertainty about the UK economy and have been focused on the broadcaster’s outlook for the fourth quarter.

While ITV has been expanding its digital and production businesses, ads still accounted for about half the company’s revenue last year.

The shares reversed an earlier drop to gain 1.3 per cent earlier in London.