Los Angeles, California(CNN) -- Christina Aguilera signed her name to a divorce petition that was filed against husband Jordan Bratman in Los Angeles County Superior Court on Thursday. The 29-year-old singer-actress cited "irreconcilable differences" as the cause of the split from the 33-year-old music executive she married five years ago. Aguilera's petition said a prenuptial agreement should dictate how they separate their assets. That agreement called for Jordan to get none of the money Aguilera earned before, during or after their marriage. She is asking the judge to grant joint legal and physical custody of the couple's 2-year-old son, Max. "Although Jordan and I are separated, our commitment to our son Max remains as strong as ever," Aguilera said in a statement released Tuesday through her representative. Aguilera co-stars with Cher in "Burlesque," a major feature film set for a Thanksgiving release.
Aguilera wants joint custody of her son . The singer-actress filed for divorce Thursday . Her petition says the couple had a prenuptial agreement .