Lady GaGa's 'The Fame Monster' was the biggest selling album of 2010.

The 'Telephone' singer's record - a repackaged version of her earlier disc, 'The Fame', with an additional eight tracks - sold 5.8 million copies across the globe, according to the United World Chart, compiled by website mediatraffic.de.

Upon hearing the news Gaga tweeted, writing: "'The Fame Monster' was named the best-selling album of 2010!

"I'm so excited for the future, believe + work hard, you will achieve your dreams (sic)."

The eccentric singer's album beat Eminem, who's 'Recovery' sold 5.7 million copies to land him in second place on the chart, while Canadian teen singing sensation Justin Bieber came in third with 5.6 million sales of his 'My World' albums.

Gaga also said she will be making an announcement about her new album 'Born This Way' at midnight on New Year's Eve.

Meanwhile, the singer has been defended by John Lennon's widow, Yoko Ono, after fans of her ex-husband's band The Beatles criticised Gaga or playing a piano belonging to the star.

Yoko told the Daily Mail newspaper: "I think her playing John's piano was wonderful. Because she's an artist, she's fearless and she pushes every limit, which we both always adored."

United World Chart top 20, as complied by mediatraffic.de:

1. Lady Gaga - The Fame (Monster) - 5.8 million copies

2. Eminem - Recovery - 5.7 million copies

3. Justin Bieber - My Worlds - 5.6 million copies

4. Lady Antebellum - Need You Now - 3.6 million copies

5. Taylor Swift - Speak Now - 3.5 million copies

6. Susan Boyle - The Gift - 3.0 million copies

7. Black Eyed Peas - The E.N.D. - 3.0 million copies

8. Michael Buble - Crazy Love - 3.0 million copies

9. Sade - Soldier Of Love - 2.3 million copies

10. Alicia Keys - The Element Of Freedom - 2.3 million copies

11. Katy Perry - Teenage Dream - 2.2 million copies

12. Take That - Progress - 2.2 million copies

13. Susan Boyle - I Dreamed A Dream - 2.1 million copies

14. Ke$ha - Animal - 2.1 million copies

15. Rihanna - Loud - 2.0 million copies

16. Mumford And Sons - Sigh No More - 1.8 million copies

17. Kings Of Leon - Come Around Sundown - 1.7 million copies

18. Bon Jovi - Greatest Hits - 1.7 million copies

19. Usher - Raymond V Raymond - 1.7 million copies

20. Linkin Park - A Thousand Suns - 1.7 million copies