Rihanna also is among the stars performing live at the event, and rumors have flown among fans and celebrity watchers in recent weeks that the pair may be secretly dating again -- speculation Brown's representatives have dismissed.

Grammy organizers said on Tuesday that Brown, who has three nominations including best R&B singer for his album "F.A.M.E.", had been added to the line-up for the February 12 awards show in Los Angeles.

Organizers said last month that Rihanna, who has four nominations including album of the year for "Loud", will sing with Coldplay on the Grammy stage.

Brown, 22, has skipped the Grammys since launching a violent attack on Rihanna in 2009, leaving her battered and bruised and Brown in the custody of police.

Brown publicly apologized, admitted to criminal assault in court. A judge sentenced him to five years probation, six months community service and anger management counseling. But his clean-cut image took a major blow.

Rihanna's career on the other hand soared, and she scored hits with songs like "Man Down" and "Love the Way You Lie", which dealt with violence against women.

The pair appeared to have gone their separate ways but in recent months, speculation buzzed that they had reunited after they were spotted at the same Los Angeles nightclub and put out a series of cryptic messages on Twitter.

But Brown's spokesman said in January that Brown and Rihanna were "just friends".

(Reporting By Jill Serjeant; Editing by Bob Tourtellotte)

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