EXHIBIT 24 POWER OF ATTORNEY We, the undersigned, hereby constitute Charles W. Cramb and Richard K. Willard, or either of them, our true and lawful attorneys with full power to sign for us in our name and in the capacity indicated below, the Annual Report on Form 10-K pursuant to Section 13 of the Securities Exchange Act of 1934, filed for the Company with the Securities and Exchange Commission for the year ended December 31, 2002, and any and all amendments and supplements thereto, hereby ratifying and confirming our signatures as they may be signed by our said attorneys, or either of them, to said Report and to any and all amendments and supplements to said Report. WITNESS Our Hand and Seal on the Date set forth below. Signatures Title Date - ---------------------------- ---------------------------- ------------------ /s/ JAMES M. KILTS Chairman of the Board of February 24, 2003 - -------------------------- Directors, Chief Executive James M. Kilts Officer and Director /s/ EDWARD F. DEGRAAN President, Chief February 24, 2003 - -------------------------- Operating Officer and Edward F. DeGraan Director /s/ CHARLES W. CRAMB Senior Vice President and February 24, 2003 - -------------------------- Chief Financial Officer Charles W. Cramb /s/ CLAUDIO E. RUBEN Vice President, Controller February 24, 2003 - -------------------------- and Principal Accounting Claudio E. Ruben Officer /s/ WARREN E. BUFFETT Director February 24, 2003 - -------------------------- Warren E. Buffett /s/ WILBUR H. GANTZ Director February 24, 2003 - -------------------------- Wilbur H. Gantz /s/ MICHAEL B. GIFFORD Director February 24, 2003 - -------------------------- Michael B. Gifford /s/ RAY J. GROVES Director February 24, 2003 - -------------------------- Ray J. Groves /s/ DENNIS F. HIGHTOWER Director February 24, 2003 - -------------------------- Dennis F. Hightower /s/ HERBERT H. JACOBI Director February 24, 2003 - -------------------------- Herbert H. Jacobi /s/ NANCY J. KARCH Director February 24, 2003 - -------------------------- Nancy J. Karch /s/ JORGE PAULO LEMANN Director February 24, 2003 - -------------------------- Jorge Paulo Lemann /s/ RICHARD R. PIVIROTTO Director February 24, 2003 - -------------------------- Richard R. Pivirotto /s/ MARJORIE M. YANG Director February 24, 2003 - -------------------------- Marjorie M. Yang 21