ITV is hoping to attract a new multimillion-pound sponsor for Love Island when the next batch of romance-seeking millennials hit screens next summer.

The most recent series of Love Island, won by Dani Dyer and Jack Fincham, proved to be TV gold, smashing viewing records and providing the nation’s watercooler moments over the summer.

Superdrug has been the headline sponsor of the past three series of the Majorca-set reality TV show, which the company has credited with driving sales of products including bronzer. But the retailer has decided not to sign up for a fourth year.

ITV has put the sponsorship package to the advertising market with a more than 50% price rise, targeting £3.5m from a partner for the fifth series. It is thought Superdrug paid between £2m and £2.5m to sponsor the record-setting last series.

Love Island has proved to be the most popular series ever aired on ITV2 – viewing figures at times topped 5 million – and proved that Britain’s TV industry can still make programmes that appeal to younger audiences amidst the streaming revolution.

The show was the biggest hit of the year among hard-to-reach 16- to 34-year-olds – with the exception of England’s World Cup football matches – a huge drawcard for advertisers.

The show’s success has emboldened ITV to increase the price of the sponsorship to a hefty level for a show that is not aired on the broadcaster’s main channel. Amazon UK paid £5m to sponsor Channel 4’s flagship entertainment show, The Great British Bake Off, which is also very popular with younger viewers.

It is understood that ITV has already received several dozen expressions of interest from advertisers keen to take on the headline sponsorship.

“We’ve seen unprecedented demand for this unique opportunity to become the headline sponsor of the biggest breakout TV show of recent years,” said the ITV commercial director, Kelly Williams.

ITV worked with 11 commercial partners on the last series of Love Island spanning product placement, brand licensing, podcast sponsors, in-store branding and exclusive product lines and merchandise.

Love Island has managed to pull off the increasingly difficult trick of getting young audiences more used to an on-demand world to tune in to a show at a set time each night. It has also become a creature of social media with enormous audiences on Instagram and more than 3 million people downloading the programme’s app to follow updates.

Love Island’s success also led to public screening parties around the UK, with hundreds of people heading to Boxpark Croydon in south London to watch the programme, and also the sale of 260,000 branded water bottles at £15 each.