Simon Cowell has reportedly signed a £150m deal with ITV to have the X Factor and Britain's Got Talent run until 2016.

According to the Sun, the media mogul finalised the contract after months of negotiations between the broadcaster and his production company, Syco.

Under the terms of the deal, he has agreed to return to one or both of the talent shows. Cowell left the X Factor in 2010 to launch the American version of the show.

But despite attracting a string of superstar judges including Gary Barlow, Sharon Osbourne and Nicole Scherzinger ratings have continued to plummet.

In 2010 it racked in an average 18 million viewers but this year could only reach the 10 million mark.

Cowell's return to the UK could boost the ratings for the ailing show as it prepares for another panel shake-up.

Barlow and Louis Walsh have both confirmed they will leave at the end of the current series.

"Everyone wants to keep making the X Factor and BGT so it was just a case of ironing out the terms," a source said. "Simon will do one show a year at least."

If Cowell does make a comeback on both programmes he could make an additional £15m, the source added.

The new deal comes as ITV acquired the rights Israeli talent show Rising Star.

Producers hope that the programme, which will include knockout rounds and a live vote, will overshadow BBC's The Voice UK when it starts in January 2015.