Bill Harvey Becomes the Chief Executive Officer of Alliant Energy
Madison, Wisconsin, United States July 1, 2005

Transition to CEO Consistent with Board's 2004 Succession Plan

Bill Harvey becomes the Chief Executive Officer of Alliant Energy (NYSE: LNT) today succeeding Erroll B. Davis, who announced in early May he would step down from the CEO position at the end of June.

"I'm excited and honored to have the opportunity to lead Alliant Energy," said Bill Harvey. "I consider it a privilege to head up the employee team at this fine company and, along with that team, I am committed to delivering superior value to both our customers and our shareowners."

"The Board of Directors and I have tremendous confidence in Bill's ability to assume the role of President and CEO," said Erroll B. Davis, Alliant Energy's Chairman of the Board and former CEO. "Bill's experience in strategy, operations and leadership prepared him well for the CEO role."

Harvey joined WPL Holdings in 1986 as Vice President and Associate General Counsel. Since that time, he has successfully held a variety of positions including General Counsel and head of Gas Operations and Senior Vice President in charge of power production, gas operations, legal affairs and administrative services. Upon the formation of Alliant Energy in 1998, he was elected Executive Vice President in charge of generation and President of WP&L. Prior to joining WPL Holdings, Harvey was in private legal practice in Madison, Wis. Harvey holds a B.A. in Economics and a Juris Doctorate from the University of Wisconsin-Madison. He and his wife, Diane, reside in Madison.

Alliant Energy Corporation is an energy-services provider with subsidiaries serving more than three million customers. Providing its customers in the Midwest with regulated electricity and natural gas service remains the company's primary focus. With Alliant Energy's Second NatureT renewable energy program, you can use earth-friendly "green power" created by wind and biomass. You can have 25 percent, 50 percent or even 100 percent of your power coming from renewable sources. A monthly contribution covers the added expense of harvesting renewable energy.