Jessie J and B.O.B is top selling collaboration of 2011
Jessie J's Price Tag featuring B.o.B is the UK's top selling collaboration of the year so far, according to the Official Charts Company.
The song, the Essex singer's second single, has sold more than 950,000 copies since its release in March.
The charts company also said that up until this week exactly half of all UK number one singles have featured a guest artist.
That's up from a quarter in 2010 and a fifth in 2009.
Other tracks in the top five selling collaborations of the year include LMFAO's Party Rock Anthem featuring Lauren Bennett and Goonrock and Maroon 5's Moves Like Jagger featuring Christina Aguilera.
Completing the top five are Pitbull's Give Me Everything featuring Ne-Yo, Afrojack and Nayer and Jennifer Lopez's On The Floor featuring Pitbull.
US star Rihanna appears on a total of three tracks in the top-selling 20.
She is currently number one with We Found Love, her joint effort with Calvin Harris.
She started the year by topping the charts with her track with Canadian rapper Drake called What's My Name.
Pitbull, Calvin Harris, Chris Brown and David Guetta each have two tracks in the top 20.