EXHIBIT 10.21

AMENDMENT NO. 6

INTERNATIONAL PAPER COMPANY

UNFUNDED SUPPLEMENTAL RETIREMENT PLAN

FOR SENIOR MANAGERS

The International Paper Company Unfunded Supplemental Retirement Plan for Senior
Managers (the “SERP”) is hereby amended effective the 1st day of January 2012 as
follows:

 

  1.

By inserting the following new language immediately at the end of the final
paragraph in the Preamble:

“The Plan was amended and restated effective January 1, 2012, to close
participation to new participants. No person who was not an Eligible Employee
and participating in the Plan as of December 31, 2011, will be eligible to
participate in the Plan after January 1, 2012. This amendment has no impact on
individuals who are participating in the Plan as Eligible Employees as of
December 31, 2011.”

 

  2.

By inserting the following new language immediately at the end of Section 3
(“Eligible Employees”):

“Notwithstanding the foregoing, the Plan was closed to new participants as of
January 1, 2012. No person who was not an Eligible Employee on or before
December 31, 2011, shall become an Eligible Employee or participate in the plan
after January 1, 2012. Eligible Employees as of December 31, 2011, shall
continue to participate in the Plan based on the current provisions of the Plan,
and this amendment shall have no impact on such participation.”