Image copyright ITV/Love Island Image caption Love Island has helped ITV attract younger audiences

ITV has blamed a fall in advertising revenue on "ongoing economic and political uncertainty".

Advertising revenue fell 8% to £769m in the first six months of the year. However, that fall was offset by good growth at ITV studios, which makes The Voice and Poldark. Its sales rose 5%.

The success of Love Island helped ITV attract more viewers in the 16-34 age bracket.

ITV's pre-tax profit fell 16% in the first half to £259m.

Executive chairman Peter Bazalgette said the company's performance was "very much as we anticipated".

"ITV is the only channel to deliver a commercial audience over five million and Love Island demonstrates young viewers engage in great TV," he said.

He also said it expects advertising revenue to be down around 4% in the third quarter.

'Formats market'

Media expert Mark Oliver said that ITV was following a trend among media companies to produce and sell TV shows, rather than rely on advertising.

He told BBC Radio 4's Today: "They have to find new sources of money in the long-term and also have to deal with the fact that every seven or 10 years, advertising goes into recession.

"When that happened in the past, ITV had to put a hold on everything, and everything stood still for five years.

"Now it has got a sizeable production business - one of the largest format producers in the world - and that continues to motor on the basis of world growth in television."

EasyJet boss Carolyn McCall is taking over as ITV's new chief executive early next year, replacing Adam Crozier.

George Salmon, equity analyst at Hargreaves Lansdown, said that with Ms McCall still to take up her role, the half year results "were never going to contain too much in the way of sharp deviations in strategy".

He added that despite Mr Crozier increasing the size of the company's production studios business "a significant portion of group revenue still comes from selling advertising space".

ITV is the largest independent non-scripted production house in the US, and Mr Salmon said: "Back at home, the phenomenal success of Love Island has provided a shot in the arm, while big names like The Voice and Britain's Got Talent remain essential viewing for millions.

"Investors will be hoping content like this, which gives the group the ability to pull in consistent viewing figures, will help ITV fend off the challenge presented by new rivals such as Netflix and Amazon."