Name:  Kathryn Marinello

Company: Ceridian

Former Position: CEO

The End: After three years as Chairman and CEO, Marinello left her position at the business services company. Marinello--named one of the 50 most powerful women in 2007 and one of the 50 highest paid women in 2008 by Forbes--offered no explanation for her resignation. "Kathy and the senior management team have made significant improvements which have strengthened Ceridian," said board member Scott Jaeckel, in a statement.

Update: On July 26 Stuart Harvey Jr. was named Ceridian's new CEO. He replaced board member Lee Kennedy, who was serving as interim CEO since Marinello's departure in January.