`The X Factor` USA mentors reportedly placed the wager at the beginning of the second series - which came to an end on 20.12.12 - that one of their act`s would be crowned the winner, which would see the victorious judge win $20,000.

A source told gossip website TMZ.com that the 53-year-old British judge lost the bet when L.A.`s act Tate Stevens - who was in the over 25s category - received the highest number of public votes and announced the champion.

But the insider insisted that Simon hasn`t displayed any signs of being a sore loser and plans to send his rival - who recently announced he would not return to the reality series next year after two seasons on the judging panel - a cheque as soon as possible.

Simon Cowell recently insisted L.A. is already regretting quitting the show to concentrate on his job as chairman of Epic Records.

However, the 56-year-old record producer - who is joined on the panel by Simon, Britney Spears and Demi Lovato - knew he would only make a short-term commitment to the series, but will continue to work with the `X Factor` boss on other projects.

He explained: "I came into this knowing that it wasn`t gonna become my life.
"Simon and I are really good friends, and he knew at some point I needed to get back to work."
sections: Celebrities