Troubled U.S. actress Lindsay Lohan once again avoided jail on Friday as a Beverly Hills judge ordered her to remain in treatment at a clinic, instead of sentencing her to jail.

"I'm serious about that [date]," Judge Elden Fox said. "You're staying there past the new year and there's a reason for that. I'm not going to be manipulated."

The "Mean Girls" star's sentence could be converted to unsupervised probation if she remains clean from drugs and alcohol until her next court hearing on Feb. 25, 2011, Judge Fox ruled.

In the meantime, the 24-year-old Lohan must return to the Betty Ford Center in Ranch Mirage, California until Jan. 3. Then she would be subject to random testing until the scheduled court hearing. Lohan has been undergoing rehab since being freed on bail Sept. 24.

If Lohan violated the terms of probation, she would be ordered to serve 180 days in jail as requested by Deputy District Attorney Danette Meyers, Judge Fox said.