Former California first lady Maria Shriver filed for divorce on Friday from former Governor Arnold Schwarzenegger, her husband of 25 years, citing "irreconcilable differences."

The decision came about six weeks after her husband acknowledged fathering a child with the couple's housekeeper, local media outlets reported.

In a divorce petition filed in Los Angeles Superior Court, Shriver requests joint custody of two minor children.

The couple, who married on April 26, 1986, did not have a prenuptial agreement, celebrity website TMZ.com said. Shriver is asking that she be awarded all separate property she acquired after their separation which was announced after Schwarzenegger stepped down as governor earlier this year.

The former California first lady moved out of the couple's Brentwood home and the couple confirmed their separation after the revelation of Schwarzenegger's extramarital affair.

The couple have four children -- Christopher, 13, Patrick, 17, and Christina, 19, and Katherine, 21.

Schwarzenegger admitted on May 17 that he had fathered a child 14 years ago with Mildred Baena, the couple's long-time housekeeper.

"After leaving the governor's office I told my wife about this event which occurred over a decade ago," Schwarzenegger said. "I understand and deserve the feelings of anger and disappointment among my friends and family.

"There are no excuses and I take full responsibility for the hurt I have caused. I have apologized to Maria, my children and my family. I am truly sorry."

He failed to mention that he confessed to Shriver only after she confronted him with the information after confirming what she had suspected about the child in an earlier confrontation with the housekeeper.

Describing Schwarzenegger's admission as "painful and heartbreaking," Shriver declined to speak further on the issue, saying: "As a mother, my concern is for the children. I ask for compassion, respect and privacy as my children and I try to rebuild our lives and heal."

Baena did not realize Schwarzenegger was her son's father until he got older and began to look like the movie icon-turned-politician, she said in an interview published last month in the British magazine Hello!.

"I knew Arnold was the father, and maybe as Joseph got older and began to look like him, he (Schwarzenegger) wondered. But he never said anything to me," Baena said.

The former housekeeper also suspected that Shriver had figured out what happened, she said during the interview.

"She would say things like, 'I'm here if you need to talk,'" Baena said. "I sensed something was up. I have so much love and respect for Maria. Finally, she asked point blank."

Shriver reacted strongly to the revelation, and cried with Baena, the housekeeper said. "We held each other and I told her it wasn't Arnie's fault, that it takes two," she said.

Before the news went public, Shriver hired a prominent divorce lawyer, Laura Wasser, to handle the matter, a source close to Shriver told US publication "People." Wasser's previous clients include Angelina Jolie, Christina Aguilera and Britney Spears.

Schriver was also reported to had been meeting with her financial advisor for some months before the decision to file the divorce petition. She has also hired a private eye to investigate Schwarzenegger's financial history and his personal life, including whether or not he has fathered more than one child out of wedlock.