FORM 10-K 12/31/09

Company

ALLIANT ENERGY CORP

Filed

February 26, 2010

Period of Report

December 31, 2009

Accession Number

0000352541-10-000009

A 10-K is a company's comprehensive annual report, required by the SEC. It includes audited financial statements, a description of the business, risk factors, and management's discussion of results. Learn more about 10-K filings →