Spector, 69, was found guilty last month in the shooting death of Clarkson at his Los Angeles area home in 2003. His lawyers, who argued the woman's death was a suicide, have vowed to appeal the conviction.
The Los Angeles Times said Thursday the guilty verdict carries a mandatory sentence of 15 years to life in prison, and the judge sentencing Spector Friday will have to decide whether to add three, four or 10 more years to the minimum sentence for the use of a firearm.
The Times said prosecutors are asking that four more years be added, while Spector's legal team is pushing for three. The judge's ruling is significant because it will determine whether Spector will be first eligible for parole at age 77, 78 or 87.
Clarkson's mother, Donna, is expected to address the court before the sentencing, the newspaper said.