Rihanna takes the lead as a finalist in 18 award categories, including Top Hot 100 Artist, Top Female Artist, Top R&B Artist and Top Dance/Electronic Artist. "Love the Way You Lie," her chart-topping collaboration with Eminem, places her as a contender in six song categories.

Meanwhile, Eminem is a finalist in 16 award categories, including Top Billboard 200 Artist, Top Artist, Top Male Artist and Top Rap Artist.

Lady Gaga follows as a finalist in 12 categories, with three releases all competing for Top Dance/Electronic Album: "The Fame," "The Fame Monster" and "The Remix."

Pop heartthrobs Bruno Mars and Justin Bieber will each vie for 11 categories and face off for Top New Artist and Top Male Artist. Other Top New Artist contenders are Ke$ha, Nicki Minaj and Taio Cruz, whose song "Dynamite" is up for five awards including Top Hot 100 Song.

The winners will be announced at the Billboard Music Awards show airing on ABC from the MGM Grand Garden Arena in Las Vegas on Sunday, May 22 at 8-11pm ET/PT. Tickets are on sale now at Ticketmaster.com.

The Billboard Music Awards take a holistic look at artist performance based on key fan interactions with music -- finalists and winners are determined by chart performance and social and streaming activity as chronicled in Billboard magazine and on Billboard.com during the eligibility period of Feb, 28, 2010 and Mar. 1, 2011.

The 46 award categories are based on measures provided by our data partners including sales data shared by Nielsen SoundScan, radio airplay monitored by Nielsen BDS, streaming data measured by Tubemogul and Nielsen BDS, social media consumption gauged by Next Big Sound and tour grosses tracked by Billboard Boxscore.

Today, Billboard launches a microsite for the 2011 Billboard Music Awards at www.Billboard.com/BBMA. Music fans can also follow news about the show and related events on Twitter (twitter.com/billboarddotcom) or Facebook (facebook.com/billboard).
 
The 2011 Billboard Music Awards is co-executive produced by Richard Beckman, CEO of Prometheus Global Media, which owns Billboard, and Don Mischer of Don Mischer Productions.
 
Here are the lead category nominations for the 2011 Billboard Music Awards. See the full list of finalists here.

Top Billboard 200 Artist

Justin Bieber
Susan Boyle
Eminem
Lady Antebellum
Taylor Swift

Top Hot 100 Artist

Ke$ha
Bruno Mars
Katy Perry
Rihanna
Usher

Top Artist

Justin Bieber
Eminem
Lady Gaga
Rihanna
Taylor Swift

Top New Artist

Justin Bieber
Taio Cruz
Ke$ha
Bruno Mars
Nicki Minaj

Top Touring Artist

Bon Jovi
Michael Buble
Lady Gaga
U2
Roger Waters