<PAGE>
                                                                    EXHIBIT 10.1
                                                                  EXECUTION COPY
                         GS Capital Partners 2000, L.P.
                     GS Capital Partners 2000 Offshore, L.P.
               GS Capital Partners 2000 Gmbh & Co. Beteiligungs KG
                  GS Capital Partners 2000 Employee Fund, L.P.
                 Goldman Sachs Direct Investment Fund 2000, L.P.
                            c/o Goldman, Sachs & Co.
                                 85 Broad Street
                            New York, New York 10004


                                                               November 25, 2002

R.H. Donnelley Corporation
R.H. Donnelley Inc.
One Manhattanville Road
Purchase, NY  10577


         Re: Investment in Preferred Stock of R.H. Donnelley Corporation

Ladies and Gentlemen:

        Reference is made to the Preferred Stock and Warrant Purchase Agreement,
dated as of September  21, 2002 (the  "Purchase  Agreement"),  by and among R.H.
Donnelley Corporation,  a Delaware corporation (the "Company") and the investors
listed in Schedule A thereto (the "Purchasers").  Capitalized terms used but not
otherwise  defined herein shall have the meanings  ascribed to such terms in the
Purchase Agreement.

        This will confirm our agreement as follows:

        1.      PURCHASE AND SALE.

                1.1.  The Company and the Purchasers hereby agree, subject to
the terms and conditions of this letter agreement, that the Company will sell to
the  Purchasers  and the  Purchasers  will  purchase from the Company (i) 70,000
shares of Series B-1 Preferred Stock (the "November Shares") created pursuant to
the Company's  Certificate of  Designations in the form of EXHIBIT A attached to
this letter agreement (the "B-1 Certificate of Designations")  and (ii) Warrants
to purchase  577,500 shares of Common Stock in  substantially  the form attached
hereto as EXHIBIT B (the "November  Warrants"),  for an aggregate purchase price
of  $70,000,000  (the  "Proceeds").  The Proceeds paid to the Company  hereunder
shall reduce, on a  dollar-for-dollar  basis, the cash component of the Purchase
Price  payable at the  Closing  Date for the  Preferred  Stock and the  Warrants
pursuant to the Purchase  Agreement.  Unless the November Shares are repurchased
by the Company  prior to the date the Sprint  Purchase  Agreement is  terminated
prior to the closing thereof,  the November Shares issued hereunder shall reduce
on a  share-for-share  basis  the  number  of  Preferred  Shares  to  which  the
Purchasers shall be entitled at the Closing, pursuant to the Purchase Agreement.
The November Warrants issued hereunder shall reduce on a  share-for-share  basis
the number of Warrants to which the Purchasers shall be entitled at the

<PAGE>
Closing  pursuant to the  Purchase  Agreement.  The closing of the  transactions
contemplated by this letter agreement (the "November  Closing") shall take place
on the date hereof  (the date of such  closing  being  referred to herein as the
"November  Closing  Date").  The  number of  November  Shares  and the number of
November  Warrants to be purchased by each Purchaser at the November Closing and
the portion of the Proceeds to be paid by each Purchaser at the November Closing
in exchange  therefor,  shall be as specified in SCHEDULE A hereto (with respect
to each such Purchaser, such Purchaser's "Specified Purchase Price").

                1.2. At the November Closing: (i) the Company will deliver to
the  Purchasers  certificates  for the November  Shares to be sold in accordance
with the provisions of SECTION 1.1 hereto registered in the respective names and
proportions set forth in SCHEDULE A hereto; (ii) the Company will deliver to the
Purchasers certificates for the November Warrants, to be sold in accordance with
the provisions of SECTION 1.1 hereto, in each case duly executed in favor of the
respective  names and in the proportions  set forth in SCHEDULE A hereto;  (iii)
subject to SECTION 6 hereof,  each  Purchaser,  in full payment for the November
Shares  and the  November  Warrants,  will  deliver to the  Company  immediately
available  funds, by wire transfer to such account as the Company shall specify,
such  Purchaser's  Specified  Purchase Price;  and (iv) each party shall take or
cause to happen such other  actions,  and shall  execute and deliver  such other
instruments or documents, as shall be required under SECTION 2 hereof.


        2.      CONDITIONS. The November Closing is subject to the following
conditions:

                2.1.  CONDITIONS OF PURCHASE.  The obligations of each Purchaser
to purchase  the  November  Shares and the  November  Warrants  at the  November
Closing  are  subject  to  satisfaction  or  waiver  of  each  of the  following
conditions on or prior to the November Closing Date.

                      (i) Each of the conditions contained in Sections 5.01(a),
                (b),  (c),  (d),  (e),  (g)(A),  (l)  and  (m) of  the  Purchase
                Agreement shall be satisfied on or prior to the November Closing
                as if set forth in their  entirety  herein and applicable to the
                transactions contemplated hereby. For further clarification, for
                purposes  hereof,  where  appropriate,  each  reference  in such
                sections  to "the  date of this  Agreement"  shall be  deemed to
                refer to the date of this letter  agreement,  each  reference to
                the  "Closing  Date"  shall be deemed to refer to the  "November
                Closing Date" and each  reference to "this  Agreement"  shall be
                deemed to refer to this letter agreement.

                      (ii) The B-1 Certificate of Designations shall have been
                duly filed with the  Secretary  of State of  Delaware  and shall
                have become effective and shall be in full force and effect;

                      (iii) All waivers and consents from third parties that the
                Purchasers   reasonably  believe  necessary  or  appropriate  in
                connection  with the  transactions  contemplated  by this letter
                agreement  shall have been  received  by the Company in form and
                substance reasonably  satisfactory to the Purchasers,  including
                without  limitation a written  confirmation  from JPMorgan Chase
                Bank under the Credit

<PAGE>
                Agreement,  dated as of June 5, 1998,  by and among the Company,
                R.H.   Donnelley,   Inc.,   The   Chase   Manhattan   Bank,   as
                Administrative  Agent and the Lenders party thereto,  as amended
                by the First Amendment to Credit Agreement, dated as of March 4,
                1999, by and among the Company,  R.H. Donnelley,  Inc. The Chase
                Manhattan Bank, as  Administrative  Agent, and the Lenders party
                thereto  (together,  the "Current Credit Agreement") in form and
                substance  reasonably  satisfactory  to the Purchasers  that the
                defaults  described in such  confirmation are not or will not be
                continuing as described and  conditioned  in such  confirmation;
                and

                      (iv) The Purchasers shall have received, dated the
                November  Closing  Date  and  addressed  to each  Purchaser,  an
                opinion of Jones,  Day, Reavis & Pogue,  counsel to the Company,
                substantially in the form attached as EXHIBIT C hereto;

                2.2. CONDITIONS OF SALE.  The  obligation of the Company to sell
the November Shares and the November Warrants at the November Closing is subject
to the satisfaction or waiver of each of the following conditions precedent:

                      (i) the conditions contained in Section 5.02(a), (b), (c),
                (d), and (e) of the Purchase  Agreement shall be satisfied on or
                prior to the November  Closing as if set forth in their entirety
                herein and applicable to the transactions  contemplated  hereby.
                For  further   clarification,   for   purposes   hereof,   where
                appropriate,  each  reference  in such  sections to "the date of
                this  Agreement"  shall be  deemed  to refer to the date of this
                letter agreement,  each reference to the "Closing Date" shall be
                deemed  to  refer  to  the  "November  Closing  Date"  and  each
                reference to "this  Agreement"  shall be deemed to refer to this
                letter agreement; and

                      (ii) the Purchasers shall have delivered immediately prior
                to or  concurrently  with the  November  Closing in  immediately
                available funds, by wire transfer to such account as the Company
                shall have  specified,  an amount  equal to the Proceeds to have
                been paid pursuant to Section 1 hereof.

        3.      AMENDMENTS TO PURCHASE AGREEMENT. The Purchase Agreement is
hereby amended as follows:

                3.1. If at the Closing the Company is required to issue an
additional amount of Preferred Shares to the Purchasers pursuant to Section 2.04
of the Purchase  Agreement,  the Company agrees that a similar  adjustment shall
also be made to the number of November  Shares and November  Warrants  issued to
the Purchasers  pursuant to this letter  agreement and to the Warrants issued to
the  Purchasers  pursuant  to the  Purchase  Agreement.  Section  2.04 is hereby
amended by adding "(other than the November  Shares and the November  Warrants)"
immediately before the words "(Common Stock Equivalents)" therein.


                3.2. Section 2.01 of the Purchase Agreement is hereby amended by
deleting  "$200.0  million" and by inserting  in its place  "$130.0  million or,
$200.0 million in the event the November Shares are redeemed pursuant to Section
5(a) of the B-1 Certificate of Designations

<PAGE>
by the Company  prior to the date the Sprint  Purchase  Agreement is  terminated
prior to the closing thereof".

                3.3. Solely for purposes of this letter agreement, the terms
"Indebtedness"  and "Leverage  Ratio" as used in Section  4.04(d) shall have the
meanings ascribed to such terms in the Current Credit Agreement.

                3.4. Section 4.02(b) of the Purchase Agreement is hereby amended
by deleting clause (vii) thereof.

                3.5. Section 4.04(e) of the Purchase  Agreement is hereby
amended by inserting at the end thereof:  "and other than any  transaction  that
requires the approval of the holders of the Company's common stock."

                3.6. Section 4.04(i) of the Purchase Agreement is hereby amended
by adding "and other than  dividends  from a wholly owned Company  Subsidiary to
its parent company" at the end of the first parenthetical thereof.

                3.7. Section 4.04(k) of the Purchase Agreement is hereby amended
by adding "or sell" after the word "issue" therein.

                3.8. The first sentence of Section 4.10(a) of the Purchase
Agreement is hereby amended by inserting "(i)" after the words "(any such act, a
"Transfer")  and by deleting the words  "except for," and inserting in its place
"or (ii) any November Shares or November Warrants prior to the first anniversary
of the November Closing Date, except in each case for,".

                3.9. The last sentence of Section 4.10(a) is hereby amended by
replacing it in its entirety with the following:  "The foregoing restrictions on
Transfer  shall cease to apply (i) in the case of any  Preferred  Shares  issued
upon the  exchange  of the  November  Shares,  and in the  case of any  November
Warrants,  from and after the first  anniversary  of the November  Closing Date,
(ii) in the case of any  other  Preferred  Shares  and  Warrants  issued  on the
Closing Date, from and after the first anniversary of the Closing Date and (iii)
upon the Trigger Date (as defined in the B-1  Certificate of  Designations),  so
long as, in each case,  such Transfer is made in compliance  with all applicable
requirements  of  law  and  any  necessary   governmental  approvals  have  been
obtained."


                3.10. The Company's reimbursement obligations pursuant to
Section 8.06(b)(ii) of the Purchase Agreement shall include the reasonable third
party and out-of-pocket expenses (including,  without limitation, all reasonable
fees and expenses of each  counsel,  accountants  and  consultants  of each such
party)  incurred by the  Purchasers or their  Affiliates in connection  with the
preparation,  negotiation, execution and performance of this letter agreement or
any of the transactions contemplated hereby.

<PAGE>

                3.11. Schedules 3.01(c), 3.01(d), 3.01(i)(i), 3.01(j) and 4.02
to the Purchase Agreement are amended by Schedules 3.01(c), 3.01(d), 3.01(i)(i),
3.01(j) and 4.02, respectively, to this letter agreement.

        4.      AMENDMENTS TO CERTIFICATE OF DESIGNATIONS, WARRANTS AND
REGISTRATION RIGHTS AGREEMENT.

                4.1. The Certificate of Designations governing the Preferred
Stock in the form of EXHIBIT A to the Purchase  Agreement  is hereby  amended by
deleting  EXHIBIT A to the Purchase  Agreement in its entirety and  replacing it
with the Certificate of Designations in the form attached as EXHIBIT D hereto.

                4.2. The certificate for the Warrants in the form attached as
EXHIBIT D to the Purchase  Agreement is herby  amended by deleting  EXHIBIT D to
the Purchase Agreement in its entirety and replacing it with the certificate for
the Warrants in the form attached as EXHIBIT E hereto.

                4.3. The Registration Rights Agreement in the form attached as
EXHIBIT C to the Purchase  Agreement is hereby amended by deleting  EXHIBIT C to
the Purchase  Agreement in its entirety and  replacing it with the  Registration
Rights Agreement in the form attached as EXHIBIT F hereto.

        5.      USE OF PROCEEDS.  The Company shall contribute the Proceeds to
R.H. Donnelley Inc.

        6.      CLOSING PAYMENT. On the November Closing Date, the Company
agrees to pay to each  Purchaser 1% of the portion of the Proceeds  paid by such
Purchaser to the Company on the November  Closing Date. Any obligations  owed by
the Company to the Purchasers pursuant to this Section 6 of the letter agreement
shall reduce on a  dollar-for-dollar  basis the amount payable to the Company by
the Purchasers pursuant to Section 1.1 hereof.

        7.      SUPPLEMENTAL INDENTURE. Immediately following the receipt by the
Company of the Proceeds,  the Company shall deliver to The Bank of New York (the
"Trustee") an executed copy of the  Supplemental  Indenture  (the  "Supplemental
Indenture") in the form attached as EXHIBIT G hereto.  The Company shall use its
best efforts to have the Trustee execute and deliver the Supplemental Indenture,
and any and all other  documents  required to make such  Supplemental  Indenture
effective,  to the Company,  with a copy to the  Purchasers,  promptly after the
receipt by the Company of the Proceeds.  If the Trustee has not delivered to the
Company and  Purchasers a fully executed copy of the  Supplemental  Indenture by
5:00 p.m.  New York time on November  27, 2002,  the  Purchasers  shall have the
right,  exercisable by written notice to the Company,  to require the Company to
promptly  repurchase  the  November  Shares  and the  November  Warrants  for an
aggregate price in cash equal to 101% of the Proceeds.


<PAGE>

        8.       CERTAIN RESTRICTED ACTIONS.

                 8.1. In addition to the restrictions set forth in Section 4.04
of the Purchase Agreement, from and after the November Closing Date, the Company
shall  not,  and shall  not  permit  any  Company  Subsidiary  to,  directly  or
indirectly,  take any of the following actions without the prior written consent
of  at  least  a  majority  of  the  then-outstanding  November  Shares  or  the
affirmative  vote in person or by proxy at a meeting  called for that purpose of
the holders of at least a majority of the November Shares voting thereat:

                 (i) dispose of or acquire any material assets for cash or
        equity; or

                 (ii) enter  into any  contract  which  requires  the  Company
        to make cash payments of more than $2 million in the aggregate; or

                  (iii) purchase any equity securities of the Company on the
        open market; or

                  (iv) except as disclosed on Schedule 8 to this letter
        agreement,  enter into, or amend in any material respect, any employment
        agreement  with, or other  compensation  to, any of the Chief  Executive
        Officer,  the Chief Financial  Offer, the General Counsel of the Company
        or the President of Donnelley Media; or

                  (v) amend or modify the DonTech Partnership Agreement or any
        related agreement in any material respect.


                 8.2. TERMINATION OF OBLIGATIONS. The obligations of the Company
set forth in Section 8.1 hereof shall  terminate  and no longer be of any effect
from and after the earlier to occur of (i) such time as the Purchasers no longer
hold any November  Shares or (ii) such time as the Purchasers no longer have the
right pursuant to the B-1 Certificate of Designations to elect a Director of the
Company.


        9.       APPLICABILITY  OF PURCHASE  AGREEMENT  PROVISIONS.  The partie
agree that the November  Closing is intended to be treated as an initial
closing under the Purchase  Agreement for purposes of the representations,
warranties, covenants, indemnities and agreements thereunder. In furtherance
thereof, the parties agree that:

                 9.1. All representations and warranties of the Company and the
Purchasers  made in Article III of the Purchase  Agreement shall be deemed to be
made on the date of this letter agreement and on the November Closing Date as if
set  forth  herein  in  their  entirety  and  applicable  to  the   transactions
contemplated thereby.

                 9.2. The Schedules to the Purchase Agreement (other than
Schedule A to the  Purchase  Agreement)  shall be deemed to be Schedules to this
letter  agreement and this letter  agreement  shall be deemed to be disclosed on
each  Schedule to the  Purchase  Agreement  where  disclosure  thereof  would be
appropriate.
<PAGE>

                 9.3. The provisions of Article VII of the Purchase Agreement
shall be applicable to the transactions contemplated by this letter agreement as
if set  forth  herein  in their  entirety  and  applicable  to the  transactions
contemplated hereby. In addition, the Company shall, from and after the November
Closing Date,  indemnify each of the Purchaser  Indemnified  Parties against and
hold them  harmless  from and against  all Losses  incurred by any of them based
upon,  resulting from or arising out of any actual or threatened claim,  action,
suit,   investigation  or  proceeding   ("Litigation")  against  such  Purchaser
Indemnified  Party  by any  Person  in  connection  with  (A)  the  transactions
contemplated by this letter agreement, (B) the negotiation,  execution, delivery
and  performance of this letter  agreement,  or any other document  contemplated
hereby, (C) any actions taken by any Purchaser Indemnified Party pursuant hereto
or in connection with the transactions  contemplated  hereby (whether or not the
transactions  contemplated hereby are consummated) or (D) the direct or indirect
ownership  by a Purchaser  Indemnified  Party of any  securities  of the Company
(including any Litigation to which a Purchaser  Indemnified  Party is made party
as a result thereof).

                 9.4. Except as set forth in this letter agreement, Sections
4.03,  4.04, 4.05, 4.08, 4.09, 4.10, 4.11, 4.13 and 4.15 (each as may be amended
hereby or from time to time) of the Purchase  Agreement shall be applicable from
and after the November Closing as if the November Closing were the Closing,  and
the November Shares shall be treated as if such shares are Preferred Shares.

                 10. AGREEMENT REGARDING DIVIDENDS. The Company agrees that on
and after January 31, 2003 it shall pay cash dividends on the November Shares on
a current  basis so long as it is not  precluded  from doing so under law or its
bank credit agreement or public indentures.  In furtherance thereof, the Company
shall (subject to the terms of its bank credit  agreement and public  indenture)
refrain from entering into any  agreements  which would  preclude such payments,
seek a waiver under any agreements which would prevent such payments at any time
and take whatever actions are necessary,  including  revaluing assets, to create
surplus for the purpose of paying such dividends.

                 11. DISCLOSURE. The Company shall not make any press release,
public  announcement  or filing  with any  Governmental  Entity  concerning  the
transactions  contemplated  by this letter  agreement or the Purchase  Agreement
unless mutually  agreed by the Company and the Purchasers,  except as and to the
extent that the Company shall be obligated to make any such  disclosure,  by law
or by the NYSE and then only after  consultation  with the Purchasers  regarding
the basis of such  obligation  and the  content  of such press  release,  public
announcement or filing.

                 12. ALLOCATIONS. The parties agree that, with respect to each
Purchaser,  the  portion  of the  Proceeds  payable  by each  Purchaser  will be
allocated: 90.0588% to the November Shares and 9.9413% to the November Warrants.
The parties  agree to report the sale and  purchase of the  November  Shares and
November  Warrants for all federal,  state,  local and foreign tax purposes in a
manner   consistent   with  this  allocation  and  agree  to  take  no  position
inconsistent  with  the  foregoing   (unless  otherwise   required  by  a  final
determination by the appropriate taxing authority).
<PAGE>

                 13. NO OTHER AMENDMENTS. Except as set forth in this letter
agreement,  all provisions of the Purchase  Agreement shall remain unchanged and
in full force and effect.

                 14. CERTAIN CONSENTS.

                     14.1. The Purchasers hereby consent, pursuant to Section
4.02(b) of the Purchase  Agreement,  to the  transactions  contemplated  by this
letter agreement.


                     14.2. Section 5(r) of the Purchase Agreement regarding the
Company's Senior Notes due 2010 and Senior Subordinated Notes due 2012 shall not
be amended or waived without the prior written consent of the Purchasers and the
Purchasers shall be third party beneficiaries of such Section.

                 15. MISCELLANEOUS.

                     15.1. This letter agreement shall be governed by, and
interpreted in accordance  with, the laws of the State of New York applicable to
contracts  made and to be performed in that State  without  giving effect to any
conflict of laws rules or principles  that might require the  application of the
laws of another jurisdiction.

                     15.2. The courts of the State of New York in New York
County and the United  States  District  Court for the Southern  District of New
York shall have  jurisdiction  over the parties  with  respect to any dispute or
controversy  between  them  arising  under or in  connection  with  this  letter
agreement and, by execution and delivery of this letter  agreement,  each of the
parties to this Agreement submits to the jurisdiction of those courts, including
but not limited to the IN  PERSONAM  and subject  matter  jurisdiction  of those
courts,  waives any objections to such  jurisdiction  on the grounds of venue or
FORUM NON CONVENIENS,  the absence of IN PERSONAM or subject matter jurisdiction
and any similar  grounds,  consents to service of process by mail (in accordance
with Section  15.4 of this letter  agreement)  or any other manner  permitted by
law,  and  irrevocably  agrees to be bound by any judgment  rendered  thereby in
connection with this Agreement.

                     15.3. All shares of capital stock held or acquired by each
of the  Goldman  Entities  shall  be  aggregated  together  for the  purpose  of
determining  the  availability  and  exercise of any right of each such  Goldman
Entity under this letter agreement.

                     15.4. All notices and other communications hereunder shall
be in made in the manner described in the Purchase Agreement.

                     15.5. No amendment, modification or alteration of the terms
or provisions of this letter  agreement  shall be binding on the parties  hereto
unless the same shall be in writing and duly  executed by such  parties,  except
that any of the terms or  provisions  of this letter  agreement may be waived in
writing at any time by the parties entitled to the benefits of such waived terms
or provisions. No waiver of any of the provisions of this letter agreement shall
be deemed to or shall constitute a waiver of any other provision hereof (whether
or not  similar).  No delay on the



<PAGE>

part of any party in exercising any right,  power or privilege  hereunder  shall
operate as a waiver  thereof.

                     15.6.  This letter  agreement  may be executed by facsimile
signature  and may be executed in one or more  counterparts,  each of which
shall be deemed to constitute an original, but all of which together shall
constitute but one agreement.


                     15.7. Nothing contained in this letter agreement or in any
instrument or document executed by any party in connection with the transactions
contemplated  hereby  shall  create  any  rights  in,  or be deemed to have been
executed  for the benefit of, any person that is not a party  hereto or thereto,
or, a successor or permitted assign of such a party.

<PAGE>
       Please confirm your agreement with the foregoing by signing and returning
one copy of this letter  agreement  to the  undersigned,  whereupon  this letter
agreement shall become a binding agreement between you and the Purchasers.



                             Very truly yours,


                             GS CAPITAL PARTNERS 2000, L.P.
                             By: GS Advisors 2000, L.L.C.
                                 Its General Partner


                             By: /s/ John E. Bowman
                                 ---------------------------------
                                 Name: John E. Bowman
                                 Its: Vice President


                             GS CAPITAL PARTNERS 2000 OFFSHORE, L.P.
                             By: GS Advisors 2000, L.L.C.
                                 Its General Partner


                             By: /s/ John E. Bowman
                                 ---------------------------------
                                 Name:  John E. Bowman
                                 Its:  Vice President



                             GS CAPITAL PARTNERS 2000 GmbH & CO.
                             BETEILIGUNGS KG


                             By: Goldman Sachs Management GP GmbH
                                 Its General Partner


                             By: /s/ John E. Bowman
                                 ---------------------------------
                                 Name:  John E. Bowman
                                 Its:  Managing Director


<PAGE>

                             GS CAPITAL PARTNERS 2000 EMPLOYEE FUND,
                             L.P.
                             By: GS Employee Funds 2000 GP, L.L.C.
                                 Its General Partner


                             By: /s/ John E. Bowman
                                 ---------------------------------
                                 Name:  John E. Bowman
                                 Its:  Vice President


                             GOLDMAN SACHS DIRECT INVESTMENT FUND
                             2000, L.P.
                             By: GS Employee Funds 2000 GP, L.L.C.
                                 Its General Partner


                             By: /s/ John E. Bowman
                                 ---------------------------------
                                 Name:  John E. Bowman
                                 Title:  Vice President

<PAGE>

Accepted and agreed as of
the date first written above:


R.H. DONNELLEY CORPORATION


By:     /s/ Robert J. Bush
    -----------------------------
    Name:  Robert J. Bush
    Title:  Vice President

R.H. DONNELLEY INC.


By:     /s/ Robert J. Bush
    -----------------------------
    Name:  Robert J. Bush
    Title:  Vice President