Howard Stern is reportedly ready to quit 'America's Got Talent'.

The outspoken radio star - who replaced Piers Morgan this year - is said to have dropped major hints he will not return for a second stint as a judge on the popular reality TV series amid rumours the show's format will be completely overhauled for its eight series.

A source told the MailOnline: "AGT is massively successful, but every TV show needs a refresh to make it the best it can be. At this time, there are questions over whether Howard wants to return."

Speaking on his radio show last week, the popular radio host - for whom the show moved from Los Angeles to New York - admitted he recently realised he didn't need to be "all over the television"

The show's boss Simon Cowell and NBC executives are now said to be scrambling to find ways to revamp the show. Sharon Osbourne recently confirmed she had quit and producers may now have to find two new judges to star alongside Howie Mandel before auditions begin next February.

The source added: "Neither of the Howards have signed up again yet, but it's Stern who is being vocal about the fact he may not come back.

"It will certainly depend on who the new third judge is. Simon wants every detail to be perfect.

"He was buoyed by the success of the last Britain's Got Talent, where there were two new judges. Who knows - there may even be a fourth judge brought on to AGT like the UK."

The source also denied rumours that 'The X Factor' USA judge Simon wants to sign up his new love interest Carmen Electra to be a judge on 'America's Got Talent'.