Exhibit 99.1


                            CERTIFICATION PURSUANT TO
                             18 U.S.C. SECTION 1350,
                             AS ADOPTED PURSUANT TO
                  SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

In connection with the Quarterly Report of International Paper Company (the
"Company") on Form 10-Q for the period ending March 31, 2003 as filed with the
Securities and Exchange Commission on the date hereof (the "Report"), I, John T.
Dillon, Chief Executive Officer of the Company, certify, pursuant to 18 U.S.C.
Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of
2002, that, to the best of my knowledge:

     (1) The Report fully complies with the requirements of Section 13(a) or
15(d) of the Securities Exchange Act of 1934; and

     (2) The information contained in the Report fairly presents, in all
material respects, the financial condition and results of operations of the
Company.


/s/ John T. Dillon
------------------------------------
John T. Dillon
Chairman and Chief Executive Officer
May 14, 2003

Subscribed and sworn to
before me this 14th day
of May 2003.


/s/ Paula Bauer
--------------------
Notary Public
State of Connecticut
My commission expires July 31, 2006




This certification accompanies the Report pursuant to Section 906 of the
Sarbanes-Oxley Act of 2002 and shall not, except to the extent required by the
Sarbanes-Oxley Act of 2002, be deemed filed by the Company for purposes of
Section 18 of the Securities Exchange Act of 1934, as amended.