LOS ANGELES (Reuters) - Former California first lady Maria Shriver filed for divorce on Friday from her estranged husband, Arnold Schwarzenegger, the ex-governor and film star who has admitted fathering a child out of wedlock more than a decade ago. Shriver, 55, a former television journalist and a daughter of the Kennedy political dynasty, filed papers seeking to dissolve her 25-year marriage to Schwarzenegger, 63, in Los Angeles County Superior Court, citing irreconcilable differences. According to the four-page, standard-form divorce filing, Shriver seeks unspecified spousal support and joint custody of the couple's two minor children, Patrick, 17, and Christopher, 13.