MICHAEL Jacksons mother has formally filed a petition to be appointed administrator of his estate. Katherine Jackson and her husband Joe both submitted the court papers Wednesday, but only she has asked to be put in charge of her late sons assets. Katherine is believed to be petitioning under the Independent Administrations Estate Act. The Thriller singer, who died on June 25 from a suspected cardiac arrest, named his lawyer John Branca and former music executive John McClain as co-executors in the will which was drawn up in 2002. Michael also named accountant Barry Siegel as a co-executor but he resigned from the position in August 2003 - meaning Katherine could replace him. It is unknown if she wants to take Siegels position or have Branca and McClain removed and be named as sole executor. Michaels will is believed to have a 'no contest clause - meaning anyone who disputes it is automatically cut out. Katherines lawyer L. Londell McMillan insists the 79 year old has no intention of challenging the wishes of her late son, but does want to be involved. McMillan told TMZ: She deserves a seat at the table, minimum. Were optimistic they can work something out. But Im prepared to go the distance if Mrs. Jackson directs to do so. He also revealed he is only representing Katherine and there are no plans for Joe to petition to be involved in handling his sons estate. ES A hearing to determine who will be named executor of Michaels will is set to take place on August 3. - ES