Hosiery company welcomes new CEO Martin Winkler, who is replacing Uwe Bergheim.
Ashish Sensarma, who has served as CEO since January 7, 2015, will resign at the end of the month.
Sharen Jester Turney leaves lingerie firm after 10 years at the helm.
Garry Hogarth departs the business after 10 years at the helm.
Lewis will be succeeded by current finance director Geoff Embley.
Adam Mansell, director of special projects at UKFT, will succeed Miln.
Tracy Lewis has been selected by Ernst and Young to join the panel.
Ashish Sensarma will join the company on January 7.
Philip Clarke will be replaced by Unilever executive Dave Lewis.
The board has stripped Dov Charney of his title as CEO and president.