Activist investor Carl Icahn on Thursday offered to buy all outstanding shares of U.S. truckmaker Oshkosh Corp for $32.50, a 21 percent premium to their Wednesday closing price.

Icahn, who is already Oshkosh's largest shareholder with a 9.45 percent stake, said that he plans to nominate a slate of directors for election at the company's next annual meeting and that his offer would be subject to the election of those directors.

(Reporting By Scott Malone; Editing by Gerald E. McCormick)