Britney Spears finds it "eerie" that she and Christina Aguilera make so many of the same career choices.

Both starlets rose to fame after appearing on the Disney Channel's The Mickey Mouse Club.

Now Britney is a judge on The X Factor USA, while Christina is gracing the judging panel of rival show The Voice. The X Factor debuts this week, with The Voice scheduling an episode at the same time.

"The fact I keep bumping into her is a little eerie. It's kind of odd, what are the chances! It's really kind of funny," Britney laughed to ET Online.

With the two singing shows in competition with each other, it is reminiscent of earlier days when the pop stars battled to dominate the charts.

The X Factor's creator Simon Cowell has kept the show in the spotlight by adding Britney to the judging panel.

"I was on full charm alert when I called Britney about The X Factor. I thought you don't get this opportunity very often. I'm going to be super charming, super persuasive," he confessed.

"I was trying to be very calm on the phone and put the phone down and said, YES!"