When Season 6 of The Hills kicks into high-gear next year, one familiar face will fade from the crowd. Stephanie Pratt won’t be returning to the MTV reality show she notoriously loves to hate in 2010. While the blonde baby sis of show villian Spencer Pratt is busy teling pals that her Hills departure was a private decision, a new tabloid report featured in the Dec. 21 issue of Star Magazine, paints a more sinister picture — insisting the troubled young star was fired by MTV.

“The show is her only identity. To avoid public embarrassment, her MTV bosses allowed Stephanie, 23, to make it seem like she was quitting over drama with bad girl Kristin Cavallari,” the magazine writes.

In reality, it was Stephanie’s big mouth and even bigger thirst for booze that sent her to the unemployment line, we hear.

Star snoops say Stephanie was canned by Hills producers after more than a year of publicly blasting the popular show in several press interviews — including one with Tyra Banks, during which Stephanie revealed that the pressure she felt to be perfect while appearing The Hills drove her to an eating disorder. She further pissed off MTV by calling the show “brutal” and remarking that she “couldn’t stand it. Steph’s October collar for Driving Under The Influence was the final straw for network producers, who immediately cancelled Stephanie’s contract:

“Producers like catfights and broken romances, not drama that involves breaking the law,” a spy adds. “Stephanie just became this major mess and was too much of a liability.”

The troubled celebutante recently entered rehab to treat an alcohol addiction, but friends fear she’s at a loss for what to do with the rest of her life:

“”She can’t make a living outside of the show,” says a pal. “She’s working on a handbag line, but the only place she’ll be selling those is her garage.”