MADISON - A Sun Prairie father pleaded no contest Friday to charges of repeatedly sexually assaulting his three daughters, often using a secret basement room.

The 39-year-old man was convicted of charges including three counts of repeated sexual assault of a child and three counts of possessing child pornography, all as a repeat offender.

He's due to be sentenced in about two months.

The criminal complaint said he built the room behind a false wall in his basement where he viewed child porn and had sex with the girls, who were of ages 9 to 13 when the assaults occurred between 2002 and 2007.

He is serving prison terms for prior convictions for lewd and lascivious behavior and drug possession.

(Copyright 2008 by The Associated Press. All Rights Reserved.)