Kate Gosselin says in divorce papers that her marriage to Jon is "irretrievably broken."
The star of TLC's reality show "Jon & Kate Plus 8" filed for a no-fault divorce Monday in Montgomery County Court in Pennsylvania. She said in papers that she's willing to "negotiate a fair and reasonable" settlement with her husband of 10 years.
The divorce filing was obtained Tuesday by The Associated Press. Lawyers for the couple said it contains boilerplate language common to all no-fault divorce petitions filed in Pennsylvania.
The TV series follows Jon and Kate Gosselin as they raise their eight young children, including 8-year-old twins and sextuplets who just turned 5.
Monday night's show, in which the couple announced their separation and divorce, drew a record audience of 10.6 million viewers.
Attorneys for both Jon and Kate Gosselin said Tuesday that the couple lived together on their Berks County compound until recently.
"They have been living 'separate and apart' just within the last week or two," said Jon's attorney, Charles Meyer, using a term from the divorce petition.
The court document does not explain what led to the split. But in a statement released to the media, Kate asserted that "Jon's activities" over the weekend had left her "no choice but to file legal procedures in order to protect myself and our children." She did not elaborate. Both Jon and Kate deny tabloid accusations that they cheated on each other.
"To be honest, I was hurt by Kate's statement about the divorce," Jon countered Tuesday in his own release. "I have always done everything I can to protect our family. This weekend, I was home with the kids for four days, just being a dad. No nannies, just the kids and me."
He added that while "emotions are running high for both of us right now," he hopes to "resolve things amicably."
Adding to the strain, Pennsylvania's Labor Department opened an investigation into whether the show's production is complying with state child labor laws. TLC has said it "fully complies" with state laws and regulations.
Mickey Sherman, a defense lawyer, told CBS News correspondent Terrell Brown, "When you factor in that you've got two TV stars, residuals, eight kids, and enormous amounts of money being in jeopardy, it's a mess."
The couple plan to spend equal time with their children at the $1.1 million house they moved into last year, with Kate staying elsewhere when he has custody, and Jon making other living arrangements when it's her turn, according to the statement.
Kate's lawyer, Cheryl Young, said Tuesday that the couple has already started negotiating the terms of the divorce.