Simon Cowell is playing it coy about rumours that Fergie, Britney Spears and Janet Jackson are being considered for the US version of The X Factor.

Two judges' spots on the Fox TV singing contest opened up when Paula Abdul and Nicole Scherzinger left after the first season.

Cowell said that two women will replace them, but he declined to comment on who is being considered.

"There's been a load of speculation, some true, some not true," Cowell said.

He added that he had waited to see who was interested enough to ask about joining the show before focusing on the search.

Judge Antonio "LA" Reid confirmed there had been discussions about adding Whitney Houston but no contact was made with her. Whitney died on February 11.

Meetings will be held over the next few weeks with "a number of people", Cowell said, primarily to make it clear to contenders how much of a time commitment X Factor represents.

He did not shed much light on the departures of Abdul and Scherzinger, saying only that shows evolve and "this time it was decided to do it sooner or later". He said the two have been "incredibly gracious and respectful" and he is looking forward to working with them again.

With host Steve Jones' exit, Cowell said he wants to switch to a two-host format that would better suit the show and the amount of information that needs to be explained, entertainingly, to viewers.

He did not say who might be hired but said they could be people who do not have "host" on their resume. He is not looking far for new judges and MCs, Cowell indicated, saying "it's important we have more Americans on the show".