KANSAS CITY, Mo. (AP) ¿ Sprint Nextel Corp. says the most-senior member of its board of directors is stepping down after almost 12 years. The wireless carrier disclosed in a regulatory filing Friday that Irvine O. Hockaday Jr. won't stand for re-election to the board at the company's annual stockholders' meeting on May 12. Sprint says Hockaday wasn't leaving because of "any matter relating to the company's operations, policies or practices." Hockaday has been on the Overland Park, Kan.-based company's board since June 1997. He served as chief executive of Hallmark Cards Inc. from 1985 to 2001. He also serves on the boards of Ford Motor Company, Estee Lauder Inc. and Crown Media Holdings Inc.