cHRIS bROWN CHARGED WITH 2 FELONIES..

LOS ANGELES - Chris Brown has been charged with two felonies stemming from an argument with his girlfriend, Rihanna , court documents show.

Brown is expected to be arraigned Thursday afternoon on charges of assault likely to cause great bodily injury and making criminal threats. The 19-year-old R&B singer remains free on $50,000 bail.

The felony complaint handed down in court Thursday morning identifies Brown's alleged victim only as "Robyn F." Rihanna 's real name is Robyn Rihanna Fenty.

If convicted, the possible sentence ranges anywhere from probation to four years and eight months in state prison, said district attorney's spokeswoman Sandi Gibbons.

Los Angeles police arrested Brown on Feb. 8 and booked him on suspicion of making criminal threats. Police said at the time a woman identified Brown as her attacker during an early morning dispute in an upscale Los Angeles neighborhood.

A phone message left for Brown's attorney, Mark Geragos, was not immediately returned Thursday. Brown's publicist Tony Knight said any statement would likely come from Geragos after today's hearing.

Rihanna 's spokesperson had no comment on the charges filed against Brown.

Brown issued a statement a week after the incident saying that he was "sorry and saddened" about the incident. Rihanna also later issued a statement, saying she wouldn't comment on the alleged beating at the request of authorities. She thanked fans for their support.

Brown's arrest has been a dent in the "Run It!" singer's squeaky-clean image, and compelled sponsors to drop him or not renew his deals.

The alleged attack also came hours before the couple were scheduled to appear and perform at the Grammy Awards. Both were no-shows for event.