Britney Spears will be performing at the MTV Video Music Awards, in her first major show in three years.The 25-year-old will open the ceremony in Las Vegas on Sunday, performing her new single Gimme More.The dance track - produced by Danja, a protégé of hip-hop producer Timbaland - premiered online earlier this month.The appearance comes after a bumpy year for the singer, who's been working to get her career back on track.She was admitted to rehab in February after being photographed shaving her head, following the breakdown of her marriage to Kevin Federline.But the singer returned to stage in May, playing a series of low-key gigs in California.Her divorced was finalised last month, but she's currently embroiled in a bitter custody battle over her sons Sean Preston and Jayden James.© Independent Television News Limited 2007. All rights reserved.