EXHIBIT 4.6


                          FIRST SUPPLEMENTAL INDENTURE

     THIS FIRST  SUPPLEMENTAL  INDENTURE  dated as of  September  28, 2004 (this
"Supplemental  Indenture"),  is  entered  into  by  and  among  Pioneer  Natural
Resources Corporation, a Delaware corporation ("Pioneer"),  Evergreen Resources,
Inc.,  a Colorado  corporation  (the  "Company"),  and Wachovia  Bank,  National
Association,  the  successor to First Union  National  Bank, a national  banking
association,  as trustee (the "Trustee").  Capitalized terms used herein and not
otherwise  defined  have the  meanings  set forth in the  Indenture  referred to
below.

                                    RECITALS

     A. The Company has  heretofore  executed  and  delivered  to the Trustee an
indenture  dated as of December 18, 2001 (the  "Indenture"),  providing  for the
issuance  of  4.75%  Senior  Convertible  Notes  due  2021 of the  Company  (the
"Securities").

     B. The  Conversion  Price is equal to $25.00,  pursuant to the  two-for-one
split of Evergreen Common Stock (as defined below) effective September 16, 2003.

     C. The Company has entered into an Agreement and Plan of Merger dated as of
May 3, 2004, by and among Pioneer,  BC Merger Sub, Inc., a Colorado  corporation
and a wholly-owned  subsidiary of Pioneer  ("Merger Sub"),  and the Company (the
"Merger  Agreement"),  providing  for (i) the merger of Merger Sub with and into
the Company with the Company as the  surviving  corporation  and a  wholly-owned
subsidiary of Pioneer and (ii) immediately thereafter, the merger of the Company
with and into  Pioneer  Evergreen  Properties,  LLC, a Texas  limited  liability
company  ("LLC Sub"),  with LLC Sub as the surviving  entity and a  wholly-owned
subsidiary of Pioneer (collectively, the "Merger").

     D. As a result of the Merger,  Pioneer will issue a number of shares of its
common stock, par value $0.01 per share and related shareholder rights ("Pioneer
Common Stock"), equal to approximately 21% of the shares of Pioneer Common Stock
outstanding  immediately prior to the Merger and pay approximately  $865,000,000
in cash, subject to adjustments as provided in the Merger Agreement, in exchange
for shares of common  stock,  no par value,  of the Company  ("Evergreen  Common
Stock").

     E. Pursuant to Section 2.1(d) of the Merger Agreement,  after the effective
time of the merger of Merger Sub and Evergreen  (the "Merger  Effective  Time"),
each Holder of the Securities will have the right to receive, upon conversion of
the  Securities in accordance  with the Indenture,  at the Conversion  Price and
instead of one share of Evergreen  Common Stock that such Holder  previously was
entitled to receive upon conversion,  (i) $19.50 in cash, without interest, plus
(ii)  $0.48  in  cash,   without   interest   (representing   the  Kansas   Sale
Consideration, as defined in the Merger Agreement), and (iii) 0.58175 of a share
of Pioneer Common Stock (the "Evergreen Consideration Unit").

     F. Pursuant to Section 4.11 of the Indenture,  as a condition  precedent to
any  merger  effecting  a change  in the kind and  amount  of  shares  and other
property issuable upon the conversion of the Securities, the Company and Pioneer
shall execute and deliver to the Trustee a supplemental indenture providing that
the Holder of each  Security  then  outstanding  shall have the right to convert
such Security into such other  securities and property  receivable in the merger
by a holder of Evergreen Common Stock.







     G. In accordance  with Section 11.1(a) of the Indenture the Company and the
Trustee may amend or supplement  the Indenture or the  Securities to comply with
Section 4.11 without notice to or consent of any Securityholder.

     H. The Company and Pioneer  desire and have  requested the Trustee to enter
into this  Supplemental  Indenture  for the purpose of amending the Indenture to
provide that, upon conversion of the Securities under the Indenture, a Holder of
Securities will receive one Evergreen  Consideration  Unit in lieu of each share
of  Evergreen  Common  Stock to which  such  Holder  otherwise  would  have been
entitled upon conversion.

     I. Each of the Company and Pioneer has duly  authorized  the  execution and
delivery of this Supplemental Indenture.

                                   AGREEMENTS

     NOW,  THEREFORE,  in  consideration of the foregoing and for other good and
valuable consideration, the receipt of which is hereby acknowledged, the parties
hereto  hereby  covenant  and agree for the equal  and  ratable  benefit  of the
Holders of the Securities as follows:

     Section 1.  Confirmation  of  Original  Indenture.  Except as  amended  and
supplemented hereby, the Indenture is hereby ratified,  confirmed and reaffirmed
in all respects.  The Indenture and this  Supplemental  Indenture shall be read,
taken and construed as one and the same instrument.

     Section 2.  Definitions.  Section 1.1 of the Indenture is hereby amended as
follows:

     (a) The definition of  "Conversion  Rate" is hereby amended and restated in
its entirety to read as follows:

            "Conversion Rate" means the  number of Evergreen Consideration Units
     into which each $1,000 principal amount of Securities is convertible, which
     is determined  by dividing  $1,000 by  the Conversion  Price at  such time,
     rounded to three decimal places  (rounded up  if the  fourth decimal  place
     thereof  is 5 or more  and otherwise  rounded down). The Conversion Rate at
     September 28, 2004, is 40 ($1,000 / $25.00).

     (b) The definition of "Conversion  Value" is hereby amended and restated in
its entirety to read as follows:

            "Conversion Value" of a Security as of any date means the sum of (A)
     the product of the Sale Price of a share of  Pioneer Common Stock times the
     number of shares of Pioneer Common Stock into which the Security could then
     be converted  (assuming that the Security was  convertible as of such date)
     plus (B) the  product of  the Cash Component times  the number of Evergreen
     Consideration  Units  into  which  the  Security  could  then  be converted
     (assuming that the Security was convertible as of such date).

     (c) The definition of "Ex-Dividend  Time" is hereby amended and restated in
its entirety to read as follows:



                                        2





            "Ex-Dividend  Time"  means,   with  respect  to   any  issuance   or
     distribution on shares of Pioneer Common Stock, the first date on which the
     shares  of  Pioneer  Common  Stock  trade  regular  way  on  the  principal
     securities  market on  which the  shares of  Pioneer Common  Stock are then
     traded without the right to receive such issuance or distribution.

     (d) The  definition of "Record Date" is hereby  amended and restated in its
entirety to read as follows:

            "Record   Date"  shall   mean,   with  respect   to  any   dividend,
     distribution or other  transaction or  event in which the holders of shares
     of Pioneer  Common Stock  have the right to receive any cash, securities or
     other property or  in which  the shares  of Pioneer Common  Stock (or other
     applicable security) is exchanged for or converted into any combination of
     cash,  securities or other property,  the date fixed  for determination  of
     stockholders  entitled to receive such cash,  securities or other  property
     (whether  such  date is  fixed by  the Board  of Directors  or by  statute,
     contract or otherwise).

     (e) The  definition  of "Sale Price" is hereby  amended and restated in its
entirety to read as follows:

         "Sale Price" of the shares of Pioneer Common Stock on any date means:

       (1) the closing per  share  sale price  (or, if  no closing sale price is
       reported,  the average of the bid and ask prices or,  if more than one in
       either case,  the average  of the average bid  and average ask prices) on
       such date as  reported in  the composite  transactions for the  principal
       United States securities exchange  on which the  shares of Pioneer Common
       Stock are traded, or

       (2) if Pioneer Common Stock is not  listed on a United States national or
       regional securities exchange,  as reported by the National Association of
       Securities Dealers Automated Quotation System or its successors.

     (f) The definition of "Cash Component" is hereby added to the Indenture and
shall read as follows:

         "Cash Component"  means the cash portion of the Evergreen Consideration
     Unit, which is $0.48, without interest."

     (g) The definition of "Evergreen Consideration Unit" is hereby added to the
Indenture and shall read as follows:

         "Evergreen Consideration  Unit"  means 0.58175  of a  share of  Pioneer
     Common Stock plus the Cash Component.

     (h) The  definition  of  "Pioneer  Common  Stock"  is  hereby  added to the
Indenture and shall read as follows:

         "Pioneer Common Stock"  means  the  common  stock  of  Pioneer  Natural
     Resources Company,  a Delaware corporation ("Pioneer"), $0.01 par value, as
     it exists  on the  date  of  this  Indenture,  as  heretofore  amended  and
     supplemented,  and any shares  of any class or classes  of Capital Stock of

                                        3





     Pioneer resulting  from  any reclassification  or reclassifications thereof
     and which have no preference in  respect of dividends or of amounts payable
     in the  event  of any  voluntary or involuntary liquidation, dissolution or
     winding-up  of the  Company  and which  are not  subject to  redemption  by
     Pioneer; provided, however,  that if at any  time there shall be  more than
     one such resulting class, the shares of each such class then so issuable on
     conversion of Securities shall be substantially in the proportion which the
     total  number  of  shares   of  such    class  resulting   from  all   such
     reclassifications bears to  the total number of  shares of all such classes
     resulting from all such reclassifications."

     Section 3.  Conversion.  Article IV of the Indenture is hereby  amended and
restated in its entirety to read as set forth on Annex A hereto.

     Section  4.  Conversion  Arrangement  on  Repurchase.  Section  5.14 of the
Indenture is hereby amended and restated in its entirety to read as follows:

              Section 5.14   Conversion Arrangement on Repurchase
              Any Securities required  to be  repurchased under  this Article V,
       unless surrendered  for conversion  before the  close of  business on the
       Optional Repurchase Date,  may be deemed to be purchased from the Holders
       of  such  Securities for  an amount  in cash  not less  than the Optional
       Repurchase Price,  by one or more investment bankers  or other purchasers
       who may  agree  with the  Company to  purchase such  Securities  from the
       Holders, to convert them into shares of Pioneer Common Stock or Evergreen
       Consideration  Units  and  to  make payment  for such  Securities  to the
       Trustee in trust for such Holders.

     Section 5.  Waiver of Defaults  and Events of  Default.  Section 8.4 of the
Indenture is hereby amended and restated in its entirety to read as follows:

              Section 8.4    Waiver of Defaults and Events of Default
              Subject to Sections  8.7 and 11.2,  the Holders  of a  majority in
       principal  amount of  the Securities  then outstanding  by notice  to the
       Trustee  may  waive an  existing  default  or Event  of  Default  and its
       consequence, except a default  or Event of Default  in the payment of the
       principal of or  interest on  any Security,  a failure  by the Company to
       convert any Securities into  Evergreen Consideration Units or any default
       or Event of Default in respect of any  provision of this Indenture or the
       Securities which,  under  Section 11.2,  cannot  be  modified or  amended
       without the  consent of  the Holder  of each  Security  affected.  When a
       default or Event of Default is waived, it is cured and ceases.

     Section 6. Change of Control.  The definition of the "Change of Control" in
Section 12.1 of the Indenture is hereby amended as follows:

     (a)  Clause (4) of  Section  12.1 is hereby  amended  and  restated  in its
entirety to read as follows:

              (4) the  closing  price  (determined  in accordance  with  Section
       4.6(d) of this Indenture) of Pioneer  Common Stock for  any five  Trading
       Days within:

                       (i) the period of  the ten Trading Days immediately after
              the later of the  Change in Control or the  public announcement of
              the  Change in  Control,  in  the  case  of a  Change  in  Control
              resulting  solely  from   a  Change  in   Control  under   Section
              12.1(a)(1), or

                                        4





                       (ii) the  period  of the  ten  Trading  Days  immediately
              preceding  the  Change in  Control,  in the  case  of a  Change in
              Control  resulting   from  a  Change  in   Control  under  Section
              12.1(a)(2) or (3),

              plus the  Cash  Component  is  at  least  equal  to  105%  of  the
              Conversion Price  in effect  on such  Trading  Day  plus the  Cash
              Component; or

     (b)  Clause (5) of  Section  12.1 is hereby  amended  and  restated  in its
entirety to read as follows:

                 (5)  in the  case of  a merger  or  consolidation,  all of  the
              consideration excluding cash payments for fractional shares in the
              merger  or  consolidation  constituting  the   Change  in  Control
              consists of  common  stock  traded  on a  United  States  national
              securities  exchange or  quoted on  the NNM  (or which, will be so
              traded or quoted when issued or exchanged in  connection with such
              Change  in  Control)  and  as  a  result  of  such  transaction or
              transactions the  Securities become convertible  solely  into such
              common stock plus the Cash Component.

     Section 7. Effect of Change in Control Repurchase Notice. The last sentence
of the first  paragraph of Section 12.2 of the  Indenture is hereby  amended and
restated in its entirety to read as follows:

                     Securities  in  respect  of  which  a  Change  in   Control
              Repurchase Notice has been given by the  Holder thereof may not be
              converted into Evergreen  Consideration Units on or after the date
              of the delivery of such Change in Control Repurchase Notice unless
              such Change in  Control  Repurchase Notice  has first been validly
              withdrawn.

     Section 8. Form of 4.75% Senior Convertible Notes Due 2021.

     (a) The last  sentence of the second  paragraph of Section 1 of the form of
Security is hereby amended and restated as follows:

                     Except as provided in this Security or in the Indenture, no
              adjustments  in respect  of payments  of interest  (including  for
              conversion on any dividend or distributions or interest (including
              Contingent Interest))  on any Security  surrendered for conversion
              on any dividend or distributions or interest (including Contingent
              Interest) on  Pioneer  Common Stock  or the  Cash Component issued
              upon conversion shall be made upon the conversion of any Security.

     (b) Section 8 of the form of Security is hereby amended and restated in its
entirety to read as set forth on Annex B hereto.

     (c) Section 9 of the form of Security is hereby amended and restated in its
entirety to read as follows:

                     9.  Conversion Arrangement on Call for Redemption
              Any  Securities  called for  redemption,  unless  surrendered  for
              conversion  before the  close  of  business  on the  Business  Day
              immediately  preceding  the  Redemption Date,  may be deemed to be
              purchased from the  Holders of such  Securities  at an  amount not

                                        5





              less than the Redemption Price, together with accrued interest, if
              any, to,  but not  including, the Redemption Date,  by one or more
              investment bankers or  other  purchasers  who may  agree with  the
              Company to purchase such  Securities from the Holders,  to convert
              them into Pioneer  Common Stock or  Evergreen  Consideration Units
              and to make payment for  such Securities  to the  Paying Agent  in
              trust for such Holders.

     Section 9. Wachovia  Bank,  National  Association.  All references to First
Union National Bank, a national  banking  association,  in the Indenture and the
Security are hereby changed to "Wachovia Bank, National Association."

     Section  10.  Conversion  Notice.  The form of  Conversion  Notice  for the
Security is hereby  amended and restated in its entirety to read as set forth on
Annex C hereto.


     Section 11. Miscellaneous.

     (a) Execution of Supplemental  Indenture.  This  Supplemental  Indenture is
executed and shall be construed as an indenture  supplemental  to the  Indenture
and, as provided in the Indenture,  this Supplemental  Indenture forms a part of
the Indenture.

     (b) NEW YORK LAW TO GOVERN. THE INTERNAL LAW OF THE STATE OF NEW YORK SHALL
GOVERN AND BE USED TO CONSTRUE THIS  SUPPLEMENTAL  INDENTURE BUT WITHOUT  GIVING
EFFECT TO  APPLICABLE  PRINCIPLES  OF  CONFLICTS  OF LAW TO THE EXTENT  THAT THE
APPLICATION OF THE LAWS OF ANOTHER JURISDICTION WOULD BE REQUIRED THEREBY.

     (c)  Counterparts.  The  parties  may sign any  number  of  copies  of this
Supplemental  Indenture.  Each signed copy shall be an original, but all of them
together represent the same agreement.

     (d) Effect of Headings.  The Section  headings  herein are for  convenience
only and shall not affect the construction hereof.

     (e) The  Trustee.  The  Trustee  shall  not be  responsible  in any  manner
whatsoever for or in respect of the validity or sufficiency of this Supplemental
Indenture or for or in respect of the recitals  contained  herein,  all of which
recitals are made solely by Pioneer and the Company.








                  [Remainder of page intentionally left blank]


                                        6





     IN WITNESS  WHEREOF,  the parties  hereto  have  caused  this  Supplemental
Indenture to be duly executed as of the date first above written.

       Dated:  September 28, 2004
                                     EVERGREEN RESOURCES, INC.

                                     By:    /s/ Richard P. Dealy
                                            -----------------------------------
                                            Name:  Richard P. Dealy
                                            Title:  Vice President


                                     PIONEER NATURAL RESOURCES COMPANY

                                     By:    /s/ Richard P. Dealy
                                            -----------------------------------
                                            Name:  Richard P. Dealy
                                            Title:  Vice President


                                     WACHOVIA BANK, NATIONAL ASSOCIATION,
                                       as Trustee

                                     By:    /s/ Doug Milner
                                            -----------------------------------
                                            Authorized Signatory





               Signature Page to the First Supplemental Indenture
                        (4.75% Senior Convertible Notes)









                                     ANNEX A

                                   ARTICLE IV
                                   CONVERSION

Section 4.1      Conversion Privilege

     (a) Subject to and upon compliance with the provisions of this Article,  at
the option of the Holder,  any Security or any portion of the  principal  amount
thereof  which  is an  integral  multiple  of  $1,000  may be  converted  at the
principal  amount  thereof,   or  of  such  portion   thereof,   into  Evergreen
Consideration Units, which include duly authorized, fully paid and nonassessable
shares  of  Pioneer  Common  Stock,  at  the  Conversion  Price,  determined  as
hereinafter provided, in effect at the time of conversion:

              (i) during any  Conversion Period,  if the  Sale Price  of 0.58175
       shares of Pioneer  Common Stock  for at least  20 Trading Days  in the 30
       consecutive  Trading Day period ending on the first day of the Conversion
       Period plus the Cash Component was more than 110% of the Conversion Price
       on that thirtieth Trading Day;

              (ii) during  the  five  Trading  Day  period   following   any  10
       consecutive Trading Day period in which the average of the Trading Prices
       for the Security for that 10 Trading Day period was less than 105% of the
       average Conversion Value for the Security during that period;

              (iii) during  any  period in  which the  Securities are  rated  by
       Moody's or  Standard & Poor's and the credit rating initially assigned to
       the Securities by either  Moody's or  Standard & Poor's is reduced by two
       or more ratings levels; provided, however, that the Company shall have no
       obligation to have the Securities rated;

              (iv) if the Company has called the Security for redemption, at any
       time prior to  the close of business on the day that is two Business Days
       prior to the  Redemption Date,  even if the  Securities are not otherwise
       convertible at that time; or

              (v) upon the occurrence of the corporate transactions specified in
       clause (b) of this Section 4.1.

     The Company shall  determine on a daily basis whether the Security shall be
convertible as a result of the occurrence of an event specified in clause (i) or
clause  (ii) above and, if the  Security  shall be so  convertible,  the Company
shall  promptly  deliver to the Trustee  written  notice  thereof.  Whenever the
Security  shall become  convertible  pursuant to Section 4.1, the Company or, at
the Company's written request, the Trustee in the name and at the expense of the
Company, shall notify the Holders of the event triggering such convertibility in
the manner provided in Section 4.2, and the Company shall also publicly announce
such  information  and publish it on the Company's web site. Any notice so given
shall be  conclusively  presumed  to have been duly  given,  whether  or not the
Holder receives such notice.


                                       A-1





     (b) In addition, in the event that:

              (i) (A) Pioneer distributes  to all  holders  of shares of Pioneer
       Common Stock  rights  or warrants  entitling them  (for a period expiring
       within 60 days of the Record Date for such distribution) to subscribe for
       or purchase  shares of  Pioneer  Common Stock,  at a price per share less
       than the  Trading  Price of  Pioneer Common  Stock  on the  Business  Day
       immediately preceding the announcement of such distribution,  (B) Pioneer
       distributes to  all holders  of shares of Pioneer  Common Stock,  cash or
       other assets,  debt securities  or rights  or warrants  to  purchase  its
       securities, where the Fair Market Value  (as  determined by the  Board of
       Directors of Pioneer) of  such distribution  per share of  Pioneer Common
       Stock exceeds 10% of the Trading Price of a share of Pioneer Common Stock
       on the Business Day immediately preceding the date of declaration of such
       distribution, or (C) a Change in Control of Pioneer occurs, then, in each
       case, the Security may be surrendered  for conversion at any  time on and
       after the date  that  the Company  gives notice  to the  Holders of  such
       right, which shall be not less than 20 days prior to the Ex-Dividend Time
       for such distribution, in the case of (A) or (B), or within 30 days after
       the occurrence of the  Change in Control,  in the case of (C),  until the
       earlier  of  the  close  of  business  on the  Business  Day  immediately
       preceding the  Ex-Dividend Time or the date  Pioneer  announces that such
       distribution  will not  take place,  in the  case of  (A) or (B),  or the
       earlier of 30 days after the Company's delivery of  the Change in Control
       Repurchase  Notice  or  the date  Pioneer  announces  that the  Change in
       Control will not take place, in the case of (C), or

             (ii) Pioneer  consolidates with or merges into another corporation,
       or is a party to a binding share exchange pursuant to which the shares of
       Pioneer  Common Stock would be  converted into cash,  securities or other
       property  as set  forth in Section 4.11 hereof,  then the Security may be
       surrendered for conversion at  any time from  and after the date which is
       15 days  prior  to  the  date  announced by  Pioneer as  the  anticipated
       effective time of such transaction until 15 days after the actual date of
       such transaction.

     The  Conversion  Rate, at any time,  shall equal (A) $1,000  divided by the
Conversion  Price at such time,  rounded to three decimal places  (rounded up if
the fourth decimal place thereof is 5 or more and otherwise rounded down).

     Notwithstanding  the  foregoing,  if such Security is called for redemption
pursuant to Article III or  submitted or presented  for  repurchase  pursuant to
Articles  V or XII,  such  conversion  right  shall  terminate  at the  close of
business on the second Business Day immediately  preceding the Redemption  Date,
Optional  Repurchase Date or Change in Control  Repurchase Date, as the case may
be, for such Security or such earlier date as the Holder  presents such Security
for  redemption or for purchase  (unless the Company shall default in making the
Redemption  Price,  Optional  Repurchase  Price or Change in Control  Repurchase
Price payment when due, in which case the  conversion  right shall  terminate at
the close of  business  on the date such  default is cured and such  Security is
redeemed or  purchased,  as the case may be). If such  Security is  submitted or
presented  for  purchase  pursuant  to  Article  III  and is  then  subsequently
withdrawn,  such conversion right shall no longer be terminated,  and the Holder
of such  Security  may convert such  Security  pursuant to this Section 4.1. The
number of Evergreen  Consideration  Units issuable upon conversion of a Security
shall be determined by dividing the principal  amount of the Security or portion
thereof  surrendered  for  conversion by the  Conversion  Price in effect on the
Conversion  Date.  The  Conversion  Price  is set  forth in  paragraph  8 of the
Securities and is subject to adjustment as provided in this Article IV.

                                       A-2





     Provisions of this  Indenture that apply to conversion of all of a Security
also apply to conversion of a portion of a Security.

     A  Security  in  respect  of  which a  Holder  has  delivered  an  Optional
Repurchase  Notice  pursuant  to Section  5.1 or a Change in Control  Repurchase
Notice  pursuant  to Section  12.1(c)  exercising  the option of such  Holder to
require the Company to purchase  such  Security  may be  converted  only if such
Optional  Repurchase Notice or Change in Control  Repurchase Notice, as the case
may be, is withdrawn  by a written  notice of  withdrawal  delivered to a Paying
Agent prior to the close of business on the Business Day  immediately  preceding
the Optional  Repurchase Date or Change in Control  Repurchase Date, as the case
may be, in accordance with Sections 5.9 or 12.2, respectively.

     A Holder of Securities is not entitled to any rights of a holder of Pioneer
Common Stock until such Holder has  converted its  Securities to Pioneer  Common
Stock,  and only to the extent such Securities are deemed to have been converted
into Pioneer Common Stock pursuant to this Article IV.

Section 4.2         Conversion Procedure

     To convert a Security,  a Holder must (a) complete  and  manually  sign the
conversion  notice on the back of the  Security  and  deliver  such  notice to a
Conversion  Agent, (b) surrender the Security to a Conversion Agent, (c) furnish
appropriate  endorsements and transfer documents if required by a Registrar or a
Conversion Agent, and (d) pay any transfer or similar tax, if required. The date
on which the  Holder  satisfies  all of those  requirements  is the  "Conversion
Date." As soon as  practicable  after the  Conversion  Date,  the Company  shall
deliver to the Holder through a Conversion Agent a certificate for the number of
whole shares of Pioneer Common Stock issuable upon the conversion,  cash in lieu
of any fractional  shares  pursuant to Section 4.3, and the Cash Component times
the number of Evergreen  Consideration Units (or fractions thereof) payable upon
such conversion. Anything herein to the contrary notwithstanding, in the case of
Global  Securities,  conversion notices may be delivered and such Securities may
be surrendered for conversion in accordance with the Applicable Procedures as in
effect from time to time.

     The person in whose name Pioneer  Common Stock  certificate  is  registered
shall be deemed to be a stockholder of record on the Conversion Date;  provided,
however,  that no  surrender  of a Security on any date when the stock  transfer
books of Pioneer shall be closed shall be effective to constitute  the person or
persons  entitled  to  receive  the  shares of  Pioneer  Common  Stock upon such
conversion  as the record  holder or holders  of such  shares of Pioneer  Common
Stock on such date,  but such  surrender  shall be effective to  constitute  the
person or persons entitled to receive such shares of Pioneer Common Stock as the
record  holder or holders  thereof for all  purposes at the close of business on
the next  succeeding day on which such stock transfer books are open;  provided,
further,  that such conversion shall be at the Conversion Price in effect on the
Conversion  Date as if the stock  transfer books of Pioneer had not been closed.
Upon  conversion of a Security,  such person shall no longer be a Holder of such
Security.  No payment or adjustment will be made for dividends or  distributions
on shares of Pioneer Common Stock issued upon conversion of a Security.

     Securities so  surrendered  for conversion (in whole or in part) during the
period from the close of  business on any regular  record date to the opening of
business on the next succeeding  interest payment date (excluding  Securities or
portions  thereof called for  redemption on a Redemption  Date during the period
beginning  at the close of business  on a regular  record date and ending at the
opening of business on the first Business Day after the next succeeding interest
payment date, or if such interest payment date is not a Business Day, the second

                                       A-3





such Business Day) shall also be accompanied  by payment in funds  acceptable to
the Company of an amount equal to the interest  payable on such interest payment
date on the principal  amount of such Security  then being  converted,  and such
interest  shall  be  payable  to  such  registered  Holder  notwithstanding  the
conversion  of such  Security,  subject  to the  provisions  of  this  Indenture
relating  to the  payment  of  defaulted  interest  by the  Company.  Except  as
otherwise  provided in this Section 4.2, no payment or  adjustment  will be made
for accrued  interest on a converted  Security.  If the Company  defaults in the
payment of interest  payable on such interest  payment  date,  the Company shall
promptly repay such funds to such Holder.

     Nothing in this  Section  shall  affect the right of a Holder in whose name
any Security is  registered at the close of business on a record date to receive
the interest  payable on such Security on the related  interest  payment date in
accordance  with the terms of this  Indenture  and the  Securities.  If a Holder
converts  more than one  Security  at the same  time,  the  number of  Evergreen
Consideration Units issuable upon the conversion shall be based on the aggregate
principal amount of Securities converted.

     Upon  surrender of a Security that is converted in part,  the Company shall
execute,  and the Trustee shall  authenticate  and deliver to the Holder,  a new
Security equal in principal  amount to the  unconverted  portion of the Security
surrendered.

Section 4.3         Fractional Shares

     The Company will not issue  fractional  shares of Pioneer Common Stock upon
conversion of  Securities.  In lieu  thereof,  the Company will pay an amount in
cash based upon the current  market  price  (determined  as set forth in Section
4.6(d)) of Pioneer  Common  Stock on the  Trading Day  immediately  prior to the
Conversion Date.

Section 4.4         Taxes on Conversion

     If a Holder  converts a Security,  the Company  shall pay any  documentary,
stamp or  similar  issue or  transfer  tax due on the issue of shares of Pioneer
Common Stock upon such  conversion.  However,  the Holder shall pay any such tax
which is due because the Holder requests the shares to be issued in a name other
than the  Holder's  name.  The  Conversion  Agent  may  refuse  to  deliver  the
certificate  representing Pioneer Common Stock being issued in a name other than
the Holder's name until the  Conversion  Agent  receives a sum sufficient to pay
any tax which  will be due  because  the shares are to be issued in a name other
than the  Holder's  name.  Nothing  herein shall  preclude  any tax  withholding
required by law or regulation.

Section 4.5         Pioneer to Provide Stock

     Pioneer shall, prior to issuance of any Securities hereunder, and from time
to time as may be necessary, reserve, out of its authorized but unissued Pioneer
Common Stock,  a sufficient  number of shares of Pioneer  Common Stock to permit
the conversion of all outstanding Securities into shares of Pioneer Common Stock
(in addition to the Cash Component).

     All  shares of  Pioneer  Common  Stock  delivered  upon  conversion  of the
Securities  shall be newly  issued  shares,  shall be duly  authorized,  validly
issued,  fully paid and  nonassessable  and shall be free from preemptive rights
and free of any lien or adverse claim.


                                       A-4





     Pioneer  will  endeavor  promptly  to  comply  with all  federal  and state
securities  laws  regulating  the offer and delivery of shares of Pioneer Common
Stock upon  conversion  of  Securities,  if any,  and will list or cause to have
quoted such shares of Pioneer Common Stock on each national  securities exchange
or on the Nasdaq  National  Market ("NNM") or other  over-the-counter  market or
such  other  market on which  Pioneer  Common  Stock is then  listed or  quoted;
provided,  however, that if rules of such automated quotation system or exchange
permit the Company to defer the listing of such  Pioneer  Common Stock until the
first conversion of the Securities into Pioneer Common Stock (in addition to the
Cash  Component) in accordance  with the provisions of this  Indenture,  Pioneer
covenants to list such Pioneer  Common Stock  issuable  upon  conversion  of the
Securities  (in  addition  to  the  Cash   Component)  in  accordance  with  the
requirements of such automated quotation system or exchange at such time.

Section 4.6         Adjustment of Conversion Price

     The  conversion  price as  stated in  paragraph  8 of the  Securities  (the
"Conversion  Price")  shall be  adjusted  from  time to time by the  Company  as
follows:

     (a) In case  Pioneer  shall (i) pay a dividend on Pioneer  Common  Stock in
shares of Pioneer Common Stock, (ii) make a distribution on Pioneer Common Stock
in shares of Pioneer Common Stock,  (iii) subdivide  outstanding  Pioneer Common
Stock into a greater number of shares,  or (iv) combine its outstanding  Pioneer
Common Stock into a smaller  number of shares,  the  Conversion  Price in effect
immediately  prior  thereto shall be adjusted so that the Holder of any Security
thereafter  surrendered for conversion  shall be entitled to receive that number
of shares of Pioneer Common Stock (and the Cash  Component)  which it would have
owned had such Security  been  converted  immediately  prior to the happening of
such event.  An  adjustment  made pursuant to this  subsection  (a) shall become
effective  immediately  after  the  record  date in the  case of a  dividend  or
distribution and shall become effective  immediately after the effective date in
the case of subdivision or combination.

     (b) In case Pioneer shall issue rights or warrants to all or  substantially
all holders of Pioneer Common Stock  entitling them (for a period  commencing no
earlier than the record date described  below and expiring not more than 60 days
after such record date) to subscribe  for or purchase  shares of Pioneer  Common
Stock (or securities convertible into Pioneer Common Stock) at a price per share
(or having a conversion  price per share) less than the current market price per
share of Pioneer Common Stock (as determined in accordance  with  subsection (d)
of this Section 4.6) on the record date for the  determination  of  stockholders
entitled to receive  such rights or  warrants,  the  Conversion  Price in effect
immediately prior thereto shall be adjusted so that the same shall equal the sum
of (i) the Cash  Component plus (ii) the product  determined by multiplying  (A)
the Conversion Price in effect  immediately  prior to such record date minus the
Cash Component by (B) a fraction,  of which the numerator shall be the number of
shares of Pioneer  Common Stock  outstanding on such record date plus the number
of shares which the  aggregate  offering  price of the total number of shares of
Pioneer  Common  Stock so  offered  (or the  aggregate  conversion  price of the
convertible  securities so offered, which shall be determined by multiplying the
number of shares of  Pioneer  Common  Stock  issuable  upon  conversion  of such
convertible securities by the conversion price per share of Pioneer Common Stock
pursuant  to the terms of such  convertible  securities)  would  purchase at the
current  market  price per share (as defined in  subsection  (d) of this Section
4.6) of Pioneer Common Stock on such record date,  and of which the  denominator
shall be the number of shares of Pioneer Common Stock outstanding on such record
date plus the number of  additional  shares of Pioneer  Common Stock offered (or
into  which  the  convertible  securities  so  offered  are  convertible).  Such

                                       A-5





adjustment shall be made  successively  whenever any such rights or warrants are
issued, and shall become effective immediately after such record date. If at the
end of the period during which such rights or warrants are  exercisable  not all
rights or warrants  shall have been  exercised,  the adjusted  Conversion  Price
shall be immediately readjusted to what it would have been based upon the number
of additional  shares of Pioneer Common Stock actually  issued (or the number of
shares  of  Pioneer  Common  Stock  issuable  upon   conversion  of  convertible
securities actually issued).

     (c) In case Pioneer shall distribute to all or substantially all holders of
Pioneer  Common  Stock any shares of Capital  Stock of the  Company  (other than
Pioneer  Common  Stock),  evidences of  indebtedness  or other  non-cash  assets
(including  securities  of any  person  other than  Pioneer  but  excluding  (1)
dividends  or  distributions  paid  exclusively  in  cash  or (2)  dividends  or
distributions  referred to in  subsection  (a) of this  Section  4.6),  or shall
distribute to all or substantially all holders of Pioneer Common Stock rights or
warrants to subscribe  for or purchase any of its  securities  (excluding  those
rights and warrants  referred to in subsection (b) of this Section 4.6), then in
each such case the  Conversion  Price  shall be  adjusted so that the same shall
equal the sum of (i) the Cash  Component  plus (ii) the  product  determined  by
multiplying (A) the current  Conversion  Price minus the Cash Component by (B) a
fraction of which the numerator  shall be the current market price per share (as
defined in  subsection  (d) of this Section 4.6) of Pioneer  Common Stock on the
record date  mentioned  below less the fair market value on such record date (as
determined by the Board of Directors of Pioneer,  whose  determination  shall be
conclusive evidence of such fair market value and which shall be evidenced by an
Officers' Certificate of Pioneer delivered to the Trustee) of the portion of the
Capital Stock, evidences of indebtedness or other non-cash assets so distributed
or of such rights or warrants  applicable  to one share of Pioneer  Common Stock
(determined  on the  basis of the  number  of shares  of  Pioneer  Common  Stock
outstanding  on the  record  date),  and of which the  denominator  shall be the
current  market  price per share (as defined in  subsection  (d) of this Section
4.6) of Pioneer Common Stock on such record date. Such adjustment  shall be made
successively  whenever any such  distribution is made and shall become effective
immediately after the record date for the determination of shareholders entitled
to receive such distribution.

              (1) In case Pioneer shall,  by dividend or otherwise,  at any time
       distribute  (a  "Triggering  Distribution") to  all or  substantially all
       holders  of Pioneer  Common  Stock  cash  in  an aggregate  amount  that,
       together with  the aggregate  amount of (A) any cash and  the fair market
       value  (as  determined  by  the  Board  of  Directors of  Pioneer,  whose
       determination  shall  be conclusive  evidence thereof  and which shall be
       evidenced by an Officers'  Certificate  delivered to the  Trustee) of any
       other consideration payable in respect of any tender offer by the Company
       or a  Subsidiary  of the  Company  for  Pioneer Common  Stock consummated
       within the  12 months preceding  the date  of payment  of the  Triggering
       Distribution  and  in respect  of which  no Conversion  Price  adjustment
       pursuant  to  this  Section 4.6  has  been  made and  (B) all other  cash
       distributions to all or substantially all holders of Pioneer Common Stock
       made within the 12 months preceding the date of payment of the Triggering
       Distribution  and in  respect of  which  no  Conversion  Price adjustment
       pursuant to this Section 4.6 has  been made,  exceeds an  amount equal to
       10.0% of  the  product of  the current  market price per share of Pioneer
       Common Stock  (as determined in  accordance with  subsection (d)  of this
       Section 4.6) on the Business Day  (the "Determination Date")  immediately
       preceding the day on  which  such Triggering  Distribution is declared by
       Pioneer  multiplied  by  the  number of  shares of  Pioneer Common  Stock
       outstanding  on the  Determination  Date  (excluding  shares held  in the
       treasury of Pioneer),  the Conversion  Price shall be reduced so that the
       same shall equal the sum of (i) the Cash  Component plus (ii) the product
       determined by multiplying (x) such Conversion Price in effect immediately
       prior  to the  Determination  Date  minus  the  Cash  Component  by (y) a

                                       A-6





       fraction  of which  the numerator  shall be  the current market price per
       share  of   Pioneer  Common  Stock  (as  determined  in  accordance  with
       subsection  (d)  of this  Section 4.6) on the Determination Date less the
       sum of the aggregate amount of cash  and  the aggregate fair market value
       (determined as  aforesaid in  this Section  4.6(c)(1)) of  any such other
       consideration  so  distributed,  paid or  payable  within  such 12 months
       (including, without limitation,  the Triggering Distribution)  applicable
       to one  share of  Pioneer Common Stock  (determined on  the basis  of the
       number of shares of Pioneer Common Stock outstanding on the Determination
       Date) and the denominator shall be such current market price per share of
       Pioneer Common Stock (as determined in accordance  with subsection (d) of
       this Section  4.6)  on the  Determination Date,  such reduction to become
       effective  immediately  prior to  the opening of business on the day next
       following the date on which the Triggering Distribution is paid.

              (2) In case  any tender  offer made  by the  Company or any of its
       Subsidiaries for Pioneer Common Stock  shall expire and such tender offer
       (as amended  upon  the expiration  thereof)  shall involve the payment of
       aggregate  consideration  in an  amount  (determined as  the sum  of  the
       aggregate amount of  cash  consideration  and the  aggregate fair  market
       value  (as  determined  by  the  Board  of  Directors  of  Pioneer, whose
       determination  shall  be conclusive  evidence thereof  and which shall be
       evidenced by an Officers' Certificate  delivered to the  Trustee thereof)
       of any other consideration)  that,  together with the aggregate amount of
       (A) any cash and  the  fair market  value  (as determined by the Board of
       Directors of Pioneer,  whose  determination shall be  conclusive evidence
       thereof  and which  shall be  evidenced by an  Officers'  Certificate  of
       Pioneer delivered to the Trustee) of  any other  consideration payable in
       respect  of any  other  tender  offers by  Pioneer  or any  Subsidiary of
       Pioneer  for  Pioneer  Common  Stock  consummated  within  the 12  months
       preceding  the  date  of the  Expiration Date  (as defined  below) and in
       respect of which no Conversion Price  adjustment pursuant to this Section
       4.6 has been made and (B) all cash  distributions to all or substantially
       all holders of Pioneer  Common Stock  made within the 12 months preceding
       the  Expiration  Date  and  in  respect  of  which  no  Conversion  Price
       adjustment pursuant to this Section 4.6 has been made,  exceeds an amount
       equal to 10.0% of the product  of the  current market  price per share of
       Pioneer Common Stock  (as determined in accordance with subsection (d) of
       this Section 4.6)  as of  the last  date  (the "Expiration Date") tenders
       could have been made pursuant to such tender offer (as it may be amended)
       (the last  time at  which  such  tenders  could   have been  made  on the
       Expiration Date is  hereinafter  sometimes called  the "Expiration Time")
       multiplied  by the  number of  shares of Pioneer Common Stock outstanding
       (including tendered shares but excluding  any shares held in the treasury
       of Pioneer)  at the  Expiration  Time,  then,  immediately  prior to  the
       opening of business on the day after the Expiration Date,  the Conversion
       Price shall be reduced so  that the  same shall  equal the sum of (i) the
       Cash Component plus (ii)  the product determined  by multiplying  (I) the
       Conversion Price in effect immediately prior  to close of business on the
       Expiration Date minus the Cash Component by  (II) a fraction of which the
       numerator shall be  the product of the number of shares of Pioneer Common
       Stock outstanding  (including tendered  shares but  excluding any  shares
       held in the treasury of Pioneer) at the Expiration Time multiplied by the
       current market price per share of Pioneer Common Stock  (as determined in
       accordance  with subsection  (d) of this Section 4.6)  on the Trading Day
       next succeeding  the Expiration Date and the denominator shall be the sum
       of (x) the  aggregate consideration  (determined as aforesaid) payable to
       stockholders based  on the acceptance (up to any maximum specified in the
       terms of  the  tender offer)  of all  shares  validly  tendered  and  not
       withdrawn as of the Expiration Time (the shares deemed so accepted, up to
       any such maximum,  being referred  to as the  "Purchased Shares") and (y)
       the product of  the number of  shares of Pioneer Common Stock outstanding
       (less any Purchased Shares and excluding any shares  held in the treasury

                                       A-7





       of Pionner)  at  the Expiration  Time and  the current  market price  per
       share  of   Pioneer  Common  Stock  (as  determined  in  accordance  with
       subsection (d) of  this Section  4.6) on  the Trading Day next succeeding
       the Expiration Date, such reduction to become effective immediately prior
       to the opening of business on the  day following the Expiration Date.  In
       the event that Pioneer is  obligated to  purchase shares  pursuant to any
       such tender offer, but Pioneer is permanently prevented by applicable law
       from effecting any or all such purchases or any or all such purchases are
       rescinded,  the  Conversion  Price  shall  again  be  adjusted  to be the
       Conversion Price which would have been in effect based upon the number of
       shares actually purchased.  If the application of this Section  4.6(c)(2)
       to any tender offer would result in  an increase in the Conversion Price,
       no adjustment  shall  be made  for such  tender offer  under this Section
       4.6(c)(2).

              (3) For purposes of this Section 4.6(c),  the term  "tender offer"
       shall  mean and  include  both tender  offers and  exchange  offers,  all
       references  to  "purchases"  of shares  in tender offers (and all similar
       references) shall mean and include both  the purchase of shares in tender
       offers and the acquisition of shares pursuant to exchange offers, and all
       references to  "tendered shares" (and all  similar references) shall mean
       and include shares tendered in both tender offers and exchange offers.

     (d) For the purpose of any computation  under  subsections (b), (c) and (d)
of this Section 4.6, the current  market price per share of Pioneer Common Stock
on any date shall be deemed to be the  average of the daily  closing  prices for
the 30  consecutive  Trading  Days  commencing  45 Trading  Days  before (i) the
Determination  Date or the Expiration  Date, as the case may be, with respect to
distributions  or tender offers under subsection (c) of this Section 4.6 or (ii)
the  record  date with  respect  to  distributions,  issuances  or other  events
requiring such computation  under subsection (b) or (c) of this Section 4.6. The
closing price for each day shall be the last reported sales price or, in case no
such reported sale takes place on such date, the average of the reported closing
bid and asked  prices in either case on the NNM or, if Pioneer  Common  Stock is
not  listed  or  admitted  to  trading  on the NNM,  on the  principal  national
securities  exchange  on which  Pioneer  Common  Stock is listed or  admitted to
trading  or, if not listed or  admitted  to  trading on the NNM or any  national
securities  exchange,  the last reported  sales price of Pioneer Common Stock as
quoted on NASDAQ or, in case no reported  sales takes place,  the average of the
closing bid and asked prices as quoted on NASDAQ or any comparable system or, if
Pioneer  Common  Stock is not  quoted on NASDAQ or any  comparable  system,  the
closing sales price or, in case no reported sale takes place, the average of the
closing bid and asked  prices,  as  furnished by any two members of the National
Association of Securities  Dealers,  Inc.  selected from time to time by Pioneer
for that purpose. If no such prices are available,  the current market price per
share shall be the fair value of a share of Pioneer  Common Stock as  determined
by the Board of Directors  of Pioneer  (which shall be evidenced by an Officers'
Certificate of Pioneer delivered to the Trustee).

     (e) In any case in which this Section 4.6 shall  require that an adjustment
be made following a record date or a Determination  Date or Expiration  Date, as
the case may be, established for purposes of this Section 4.6, Pioneer may elect
to defer (but only until five Business Days  following the filing by the Company
with the Trustee of the  certificate  described  in Section  4.9) issuing to the
Holder of any Security converted after such record date or Determination Date or
Expiration  Date the shares of Pioneer  Common Stock and other  Capital Stock of
Pioneer  issuable  upon such  conversion  over and above the  shares of  Pioneer
Common Stock and other  Capital Stock of Pioneer  issuable upon such  conversion
only on the basis of the Conversion  Price prior to adjustment;  and, in lieu of
the shares the  issuance of which is so deferred,  Pioneer  shall issue or cause


                                       A-8





its transfer agents to issue due bills or other appropriate evidence prepared by
Pioneer of the right to receive such shares.  If any  distribution in respect of
which an  adjustment  to the  Conversion  Price is required to be made as of the
record date or Determination  Date or Expiration Date therefor is not thereafter
made or paid by Pioneer for any reason, the Conversion Price shall be readjusted
to the  Conversion  Price  which would then be in effect if such record date had
not been fixed or such effective date or  Determination  Date or Expiration Date
had not occurred.

Section 4.7         No Adjustment

     No  adjustment  in the  Conversion  Price  shall  be  required  unless  the
adjustment  would  require  an  increase  or  decrease  of at  least  1% in  the
Conversion Price as last adjusted; provided, however, that any adjustments which
by reason of this  Section  4.7 are not  required  to be made  shall be  carried
forward and taken into account in any subsequent  adjustment.  All  calculations
under  this  Article  IV shall  be made to the  nearest  cent or to the  nearest
one-hundredth of a share, as the case may be.

     No adjustment  need be made for issuances of Pioneer  Common Stock pursuant
to a Pioneer plan for  reinvestment  of dividends or interest or for a change in
the par value or a change to no par value of Pioneer Common Stock.

     To the extent  that the  Securities  become  convertible  into the right to
receive  cash, no adjustment  need be made  thereafter as to the cash.  Interest
will not accrue on the cash.

Section 4.8         Adjustment for Tax Purposes

     The Company  shall be entitled to make such  reductions  in the  Conversion
Price,  in addition to those  required by Section  4.6, as it in its  discretion
shall determine to be advisable in order that any stock dividends,  subdivisions
of  shares,   distributions  of  rights  to  purchase  stock  or  securities  or
distributions of securities convertible into or exchangeable for stock hereafter
made by Pioneer to its stockholders shall not be taxable.

Section 4.9         Notice of Adjustment

     Whenever the  Conversion  Price or  conversion  privilege is adjusted,  the
Company shall  promptly mail to  Securityholders  a notice of the adjustment and
file  with the  Trustee  an  Officers'  Certificate  briefly  stating  the facts
requiring  the  adjustment  and the manner of computing it. Unless and until the
Trustee  shall receive an Officers'  Certificate  setting forth an adjustment of
the Conversion Price, the Trustee may assume without inquiry that the Conversion
Price has not been adjusted and that the last  Conversion  Price of which it has
knowledge remains in effect.

Section 4.10        Notice of Certain Transactions

       In the event that:

              (1) Pioneer takes any action  which would require an adjustment in
       the Conversion Price;

              (2) Pioneer  consolidates  or merges  with,  or  transfers all  or
       substantially all of its property and assets to,  another corporation and
       shareholders of Pioneer must approve the transaction; or

                                       A-9





              (3)  there is  a  dissolution  or  liquidation of  the  Company or
       Pioneer,

the Company shall mail to Holders and file with the Trustee a notice stating the
proposed  record or effective  date,  as the case may be. The Company shall mail
the notice at least ten days  before  such date.  Failure to mail such notice or
any defect therein shall not affect the validity of any transaction  referred to
in clause (1), (2) or (3) of this Section 4.10.

Section 4.11        Effect of Reclassification, Consolidation, Merger or Sale on
                    Conversion Privilege

     If any of the following shall occur,  namely: (a) any  reclassification  or
change of  shares of  Pioneer  Common  Stock  issuable  upon  conversion  of the
Securities (other than a change in par value, or from par value to no par value,
or  from  no  par  value  to par  value,  or as a  result  of a  subdivision  or
combination,  or any other change for which an adjustment is provided in Section
4.6); (b) any consolidation or merger or combination to which Pioneer is a party
other than a merger in which  Pioneer is the  continuing  corporation  and which
does not result in any  reclassification of, or change (other than in par value,
or from par value to no par value,  or from no par value to par  value,  or as a
result of a subdivision or combination) in, outstanding shares of Pioneer Common
Stock;  or (c) any sale or  conveyance  as an  entirety or  substantially  as an
entirety of the property and assets of Pioneer,  directly or indirectly,  to any
person, then Pioneer, or such successor,  purchasing or transferee  corporation,
as the case may be, shall,  as a condition  precedent to such  reclassification,
change,  combination,  consolidation,  merger,  sale or conveyance,  execute and
deliver to the Trustee a  supplemental  indenture  providing  that the Holder of
each  Security  then  outstanding  shall have the right to convert such Security
into the kind and amount of shares of stock and other  securities  and  property
(including cash)  receivable upon such  reclassification,  change,  combination,
consolidation, merger, sale or conveyance by a holder of the number of shares of
Pioneer Common Stock  deliverable  upon conversion of such Security (in addition
to the  Cash  Component)  immediately  prior to such  reclassification,  change,
combination,  consolidation,  merger,  sale  or  conveyance.  Such  supplemental
indenture shall provide for  adjustments of the Conversion  Price which shall be
as nearly  equivalent as may be practicable to the adjustments of the Conversion
Price   provided  for  in  this  Article  IV.  If,  in  the  case  of  any  such
consolidation,  merger,  combination,  sale or  conveyance,  the  stock or other
securities and property  (including  cash)  receivable  thereupon by a holder of
Pioneer Common Stock include shares of stock or other securities and property of
a person other than the successor,  purchasing or transferee corporation, as the
case may be, in such  consolidation,  merger,  combination,  sale or conveyance,
then such supplemental indenture shall also be executed by such other person and
shall contain such additional provisions to protect the interests of the Holders
of the Securities as the Board of Directors shall reasonably  consider necessary
by reason of the foregoing.  The provisions of this Section 4.11 shall similarly
apply to successive reclassifications,  changes,  combinations,  consolidations,
mergers, sales or conveyances.

     In the event the Company shall execute a supplemental indenture pursuant to
this  Section  4.11,  the Company  shall  promptly  file with the Trustee (x) an
Officers'  Certificate briefly stating the reasons therefor,  the kind or amount
of shares of stock or other  securities or property  (including cash) receivable
by Holders of the Securities upon the conversion of their  Securities  after any
such  reclassification,  change,  combination,  consolidation,  merger,  sale or
conveyance,  any  adjustment  to be made  with  respect  thereto  and  that  all
conditions  precedent have been complied with and (y) an Opinion of Counsel that
all conditions precedent have been complied with, and shall promptly mail notice
thereof to all Holders.



                                      A-10





Section 4.12        Trustee's Disclaimer

     The Trustee shall have no duty to determine  when an adjustment  under this
Article IV should be made, how it should be made or what such adjustment  should
be, but may accept as conclusive evidence of that fact or the correctness of any
such  adjustment,   and  shall  be  protected  in  relying  upon,  an  Officers'
Certificate  including the Officers'  Certificate with respect thereto which the
Company is  obligated  to file with the  Trustee  pursuant to Section  4.9.  The
Trustee makes no representation as to the validity or value of any securities or
assets  issued upon  conversion  of  Securities,  and the  Trustee  shall not be
responsible  for the  Company's  failure to comply with any  provisions  of this
Article IV.

     The  Trustee  shall  not be  under  any  responsibility  to  determine  the
correctness of any provisions  contained in any supplemental  indenture executed
pursuant  to  Section  4.11,  but  may  accept  as  conclusive  evidence  of the
correctness thereof, and shall be fully protected in relying upon, the Officers'
Certificate with respect thereto which the Company is obligated to file with the
Trustee pursuant to Section 4.11.

Section 4.13        Voluntary Reduction

     The Company from time to time may reduce the Conversion Price by any amount
for any period of time if the period is at least 20 days and if the reduction is
irrevocable  during the period if the Board of  Directors  determines  that such
reduction would be in the best interest of the Company and the Company  provides
15 days  prior  notice  of any  reduction  in the  Conversion  Price;  provided,
however, that in no event may the Company reduce the Conversion Price to be less
than the par value of a share of Pioneer Common Stock.




                                      A-11





                                     ANNEX B


8.     Conversion

Subject  to  compliance  with the  provisions  of the  Indenture,  a Holder of a
Security  may  convert the  principal  amount of such  Security  (or any portion
thereof  equal to $1,000 or any integral  multiple of $1,000 in excess  thereof)
into Evergreen Consideration Units at the Conversion Price in effect at the time
of conversion under certain circumstances described in the Indenture;  provided,
however,  that if the Security is called for redemption or subject to repurchase
upon a specific  date pursuant to Article V of the Indenture or upon a Change in
Control,  the  conversion  right will  terminate at the close of business on the
Business Day immediately  preceding the redemption date or the Change in Control
Repurchase  Date,  as the case may be, for such Security or such earlier date as
the Holder presents such Security for redemption or purchase (unless the Company
shall default in making the redemption  payment,  Optional  Repurchase  Price or
Change in Control  Repurchase Price, as the case may be, when due, in which case
the conversion  right shall  terminate at the close of business on the date such
default is cured and such Security is redeemed or purchased).

     The  Company  will  notify  Holders  of any event  triggering  the right to
convert the Security as specified above in accordance with the Indenture.

     A  Security  in  respect  of  which a  Holder  has  delivered  an  Optional
Repurchase Notice or a Change in Control Repurchase Notice exercising the option
of such  Holder to  require  the  Company to  repurchase  such  Security  may be
converted  only if such notice of exercise is withdrawn in  accordance  with the
terms of the Indenture.

     The Conversion Price is $25.00 per Evergreen Consideration Unit, subject to
adjustment under certain  circumstances.  The number of Evergreen  Consideration
Units  issuable  upon  conversion  of a Security is  determined  by dividing the
principal amount of the Security or portion thereof  converted by the Conversion
Price in effect on the Conversion Date. No fractional shares will be issued upon
conversion;  in lieu  thereof,  an amount  will be paid in cash  based  upon the
closing  price (as  defined in the  Indenture)  of Pioneer  Common  Stock on the
Trading Day immediately prior to the Conversion Date.

To  convert  a  Security,  a Holder  must (a)  complete  and  manually  sign the
conversion notice set forth below and deliver such notice to a Conversion Agent,
(b)  surrender  the  Security to a  Conversion  Agent,  (c) furnish  appropriate
endorsements  and transfer  documents if required by a Registrar or a Conversion
Agent,  and (d) pay any  transfer or similar  tax, if  required.  Securities  so
surrendered  for  conversion  (in whole or in part)  during the period  from the
close of business  on any Regular  Record Date to the opening of business on the
next succeeding Interest Payment Date (excluding  Securities or portions thereof
called for redemption or subject to repurchase  upon a specific date pursuant to
Article V of the  Indenture  or upon a Change in Control on a  Redemption  Date,
Optional  Repurchase Date or Change in Control  Repurchase Date, as the case may
be,  during the period  beginning  at the close of business on a Regular  Record
Date and ending at the opening of business on the first  Business  Day after the
next succeeding Interest Payment Date, or if such Interest Payment Date is not a
Business Day, the second such Business Day) shall also be accompanied by payment
in funds acceptable to the Company of an amount equal to the interest payable on
such Interest  Payment Date on the principal  amount of such Security then being
converted,  and  such  interest  shall  be  payable  to such  registered  Holder
notwithstanding  the  conversion of  such  Security,  subject  to the provisions

                                       B-1





of this Indenture  relating to the payment of defaulted interest by the Company.
If the  Company  defaults  in the  payment  of  interest  (including  Contingent
Interest)  payable on such  Interest  Payment Date,  the Company shall  promptly
repay such funds to such  Holder.  A Holder may  convert a portion of a Security
equal to $1,000 or any integral multiple thereof.




                                       B-2




                                     ANNEX C

                                CONVERSION NOTICE

     To convert this Security into Evergreen Consideration Units, check the box:
|_|

     To convert only part of this  Security,  state the  principal  amount to be
converted (must be $1,000 or a multiple of $1,000): $___________.

     If you want the stock  certificate  made out in another person's name, fill
in the form below:

- -------------------------------------------------------------------------------
                  (Insert assignee's soc. sec. or tax I.D. no.)

- -------------------------------------------------------------------------------

- -------------------------------------------------------------------------------

- -------------------------------------------------------------------------------
              (Print or type assignee's name, address and zip code)

                                       Your Signature:

Date:
      -----------------------------    ----------------------------------------
                                       (Sign exactly as your name appears on the
                                       other side of this Security)
*Signature guaranteed by:

By:
      ----------------------------

- -----------
*    The Signature must be guaranteed by an institution which is a member of one
     of  the  following  recognized  signature  guarantly  programs  :  (i)  the
     Securities  Transfer Agent  Medallion  Program  (STAMP);  (ii) the New York
     Stock Exchange  Medallion Program (MSP); (iii) the Stock Exchange Medallion
     Program  (SEMP);  or (iv) such other  guaranty  program  acceptable  to the
     Trustee.






                                       C-1