Another officer accused of assaulting the reporter who filmed the beating was suspended for 120 days, the department said in a press release.
The victim, Robert Davis, publicly denied he was drinking alcohol the night of his arrest and said he did nothing to provoke the beating that ended with him bloodied and handcuffed on a sidewalk.
The brutal beating of a black man by white officers led to accusations of racism and federal officials launched a civil rights probe.
The October 8 incident further sullied the reputation of a police force struggling to rebuild itself after scores of officers abandoned their posts in the chaos following Hurricane Katrina which ravaged New Orleans on Aug 29.
The officers who stayed have been accused of ignoring reports of rape and other savagery at a shelter for refugees in the city's Superdome.
Police have also been accused of making sport of shooting dogs that residents were forced to leave behind while escaping the then-flooded city.
A probe was also launched to determine why officers took luxury cars, including two vintage automobiles, from a Cadillac dealership in New Orleans in the lawless wake of the storm.