Spears planning 'Blackout' world tour?

Britney Spears has started planning a world tour to promote her Blackout album, say reports.

The troubled popstar has been practising dance routines at LA's Millennium Dance Complex, claims the New York Post.

"Britney will be leaving the country in the next few weeks, after training in privacy for a month. She is planning a global tour," said a source.

Spears was critically panned for her live comeback in 2007, when she lip-synched Blackout's lead single 'Gimme More' at the MTV Video Music Awards.

> Click here for our review of Britney's Blackout album