Oppenheimer Principal Protected Main Street Fund III(R)
                  Supplement dated September 7, 2007 to the
                      Prospectus dated December 15, 2006

     This  supplement  amends  the  Prospectus  dated  December  15,  2006.  The
Prospectus  is  revised  by  deleting  the  section  "How the Fund is  Managed,"
beginning on page 30, in its entirety and replacing it with the following:

   How the Fund is Managed

     THE MANAGER. The Manager, OppenheimerFunds,  Inc., serves as the investment
adviser to the Fund and to the Underlying  Fund. The Manager  chooses the Fund's
investments  and handles its day-to-day  business.  The Manager  carries out its
duties,  subject to the  policies  established  by the Fund's Board of Trustees,
under   an   investment   advisory   agreement   that   states   the   Manager's
responsibilities.  The agreement  sets the fees the Fund pays to the Manager and
describes  the  expenses  that the Fund is  responsible  to pay to  conduct  its
business.

     The Manager has been an investment  advisor since 1960. The Manager and its
subsidiaries and controlled  affiliates managed more than $250 billion in assets
as of June 30, 2007,  including other Oppenheimer funds with more than 6 million
shareholder accounts.  The Manager is located at Two World Financial Center, 225
Liberty Street, 11th Floor, New York, New York 10281-1008.

     Advisory Fees. Under the investment advisory  agreement,  the Fund pays the
Manager a  management  fee at an annual  rate of 0.50% per annum of the  average
annual net assets of the Fund.  That fee will apply during the  Warranty  Period
and the  Post-Warranty  Period.  The management fee will be reduced to 0.40% per
annum of average  annual net assets of the Fund in any month during the Warranty
Period following a month where the Fund's investment in equity securities is, on
average,  less than 10% of net assets. If during the Warranty Period 100% of the
Fund's assets are completely and  irreversibly  invested in the debt  portfolio,
the  management fee will be at an annual rate of 0.25% of the average annual net
assets of the Fund,  and if that  occurs the  Manager  will  further  reduce its
management fee to the extent necessary so that total annual  operating  expenses
of the Fund (other than Extraordinary  Expenses such as litigation costs) do not
exceed  1.30% for Class A  shares,  2.05% for Class B shares,  2.05% for Class C
shares  and  1.55%  for  Class  N  shares.  However,  if this  reduction  in the
management  fee is not sufficient to reduce total annual  operating  expenses to
these limits,  the Manager is not required to subsidize  Fund expenses to assure
that expenses do not exceed those limits.  Furthermore, if expenses exceed these
expense limits,  the Warranty Amount will be reduced by any expenses that exceed
those  limits.  The Manager  voluntarily  waived its  management  fee during the
Offering Period.

     A discussion regarding the basis for the Board of Trustees' approval of the
Fund's  investment  advisory  contract is  available  in the Fund's  Semi-Annual
Report to shareholders for the semi-annual period ended February 28, 2007.

     Portfolio Managers.  The Fund's portfolio is managed by Angelo Manioudakis,
Rudi W. Schadt and Sergei V.  Polevikov  who are primarily  responsible  for the
day-to-day management of the Fund's investments.

     Mr. Manioudakis has been a Vice President and portfolio manager of the Fund
since October  2004.  He has been a Senior Vice  President of the Manager and of
HarbourView  Asset  Management  Corporation  since  April 2002 and a Senior Vice
President of OFI Institutional  Asset Management,  Inc. since June 2002. He is a
portfolio  manager  and  officer  of other  portfolios  in the  OppenheimerFunds
complex.  Mr.  Manioudakis  was  Executive  Director and  portfolio  manager for
Miller,  Anderson & Sherrerd, a division of Morgan Stanley Investment Management
from August 1993 through April 2002.

     Mr.  Schadt has been a Vice  President  and  portfolio  manager of the Fund
since October 2004. He has been a Vice President,  Director of Equity  Analytics
and Risk in Product  Design and Risk  Management of the Manager  since  February
2002  and  is a  portfolio  manager  and  officer  of  other  portfolios  in the
OppenheimerFunds  complex. Prior to joining the Manager in February 2002, he was
a Director and Senior  Quantitative  Analyst from 2000 through 2001 at UBS Asset
Management and an Associate  Director,  Senior  Researcher and Portfolio Manager
from June 1997 to August 2000 at State Street Global Advisors.

     Mr. Polevikov has been an Assistant Vice President and portfolio manager of
the Fund since August 2007. He has been an Assistant Vice President of OFI since
April 19,  2004 and is a senior  research  analyst  as well as a member of OFI's
Product Design and Equity Risk Analytics  teams.  He is a portfolio  manager and
officer of other portfolios in the  OppenheimerFunds  complex.  Prior to joining
OFI, Mr. Polevikov was an Economic Research Analyst for the Federal Reserve Bank
of Dallas from May 1997 to August 1999.

     The Statement of Additional  Information  provides  additional  information
about the Portfolio Managers' compensation, other accounts they manage and their
ownership of Fund shares.

     PORTFOLIO   HOLDINGS.   The  Fund's  portfolio  holdings  are  included  in
semi-annual  and annual reports that are distributed to shareholders of the Fund
within 60 days  after the close of the  period  for which  such  report is being
made.  The Fund also  discloses  its  portfolio  holdings in its  Statements  of
Investments  on Form N-Q,  which  are filed  with the  Securities  and  Exchange
Commission  (the  "SEC") no later  than 60 days after the close of its first and
third fiscal quarters. These required filings are publicly available at the SEC.
Therefore,  portfolio  holdings of the Fund are made publicly available no later
than 60 days after the close of each of the Fund's fiscal quarters.

     A description  of the Fund's  policies and  procedures  with respect to the
disclosure  of the  Fund's  portfolio  securities  is  available  in the  Fund's
Statement of Additional Information.




September 7, 2007                                                   PS0771.004