##### Table of Contents



As filed with the Securities and Exchange Commission on
    June 27, 2007.
 
 
 Registration No. 333-143979
 
 
  UNITED STATES SECURITIES AND
    EXCHANGE COMMISSION
 Washington, D.C.
    20549
     
   Amendment No. 1
 
 
 to
 
 Form S-3
  REGISTRATION
    STATEMENT
 UNDER
 THE SECURITIES ACT OF
    1933
       Pioneer Companies,
    Inc.
 (Exact name of registrant as
    specified in its charter)
  Delaware

06-1215192(State or other jurisdiction
    of
    incorporation or organization)

(I.R.S. Employer
    Identification No.)   700 Louisiana Street,
    Suite 4300
 Houston, Texas 77002
 (713) 570-3200
 (Address, including zip code,
    and telephone number, including area code, of registrants
    principal executive offices)
  Gary L. Pittman
 Senior Vice President and Chief
    Financial Officer
 Pioneer Companies,
    Inc.
 700 Louisiana Street,
    Suite 4300
 Houston, Texas 77002
 (713) 570-3200
 (Name, address, including zip
    code, and telephone number, including area code, of agent for
    service)
      With a copy to:
 David P. Elder
 Paul E. Pryzant
 Locke Liddell & Sapp
    LLP
 600 Travis, 34th Floor
 Houston, Texas 77002
 (713) 226-1200
  Approximate date of commencement of proposed sale to the
    public:
  o
  þ
  o
  o
  o
  o
 
 
  The Registrant hereby amends this Registration Statement on
    such date or dates as may be necessary to delay its effective
    date until the Registrant shall file a further amendment which
    specifically states that this Registration Statement shall
    become effective in accordance with Section 8(a) of the
    Securities Act of 1933, or until the Registration Statement
    shall become effective on such date as the Commission, acting
    pursuant to said Section 8(a), may determine.




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The
information in this prospectus is not complete and may be
changed. The selling stockholders may not sell these securities
until the registration statement filed with the Securities and
Exchange Commission is effective. This prospectus i23s not an
offer to sell these securities and it is not soliciting an offer
to buy these securities in any state where the offer or sale is
not permitted.  SUBJECT TO COMPLETION, DATED
    JUNE 27, 2007.
 
  Preliminary Prospectus
 $120,000,000
  
 2.75% Convertible Senior
    Subordinated Notes due 2027
    and
    Shares of Common Stock Issuable Upon Conversion of the
    Notes
       
  trading-day
 
  business-day trading-day
          sm
  Investing in the notes and our common stock issuable upon
    conversion of the notes involves risks that are described in the
    Risk Factors section of this prospectus beginning on
    page 8 and the risk factors incorporated herein by
    reference from our annual and quarterly reports filed with the
    Securities and Exchange Commission.
      Neither the Securities and Exchange Commission nor any state
    securities commission has approved or disapproved of these
    securities or passed upon the adequacy or accuracy of this
    prospectus. Any representation to the contrary is a criminal
    offense.
     This date of this prospectus
    is  , 2007.




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##### 



We have not authorized any other person to provide you with
    any information or to make any representation that is different
    from, or in addition to, the information and representations
    contained in this prospectus and any prospectus supplement or in
    any of the documents that are incorporated by reference in this
    prospectus. If anyone provides you with different or
    inconsistent information, you should not rely on it. You should
    assume that the information appearing in this prospectus and any
    prospectus supplement, as well as the information contained in
    any document incorporated by reference, is accurate as of the
    date of each such document only, unless the information
    specifically indicates that another date applies.
  TABLE OF
    CONTENTS
   
 
 IMPORTANT NOTICE TO
    READERS


iSPECIAL
    NOTE REGARDING FORWARD-LOOKING STATEMENTS


iiINCORPORATION OF
    DOCUMENTS FILED WITH THE SEC


iiiPROSPECTUS
    SUMMARY


1RISK
    FACTORS


8USE OF
    PROCEEDS


16DESCRIPTION OF
    CAPITAL STOCK


16DESCRIPTION OF
    OTHER INDEBTEDNESS


19DESCRIPTION OF THE
    NOTES


19CERTAIN UNITED
    STATES FEDERAL INCOME TAX CONSIDERATIONS


46SELLING
    SECURITYHOLDERS


51PLAN OF
    DISTRIBUTION


55LEGAL
    MATTERS


57EXPERTS


57WHERE YOU CAN FIND
    MORE INFORMATION


58Consent of Deloitte & Touche LLP  
  IMPORTANT
    NOTICE TO READERS




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SPECIAL
    NOTE REGARDING FORWARD-LOOKING STATEMENTS     
  
    general economic, business and market conditions including
    economic instability or a downturn in the markets served by us; 
 
  
    the cyclical nature of our product markets and operating results; 
 
  
    the supply/demand balance for our products, including the impact
    of excess industry capacity or the construction of new industry
    capacity; 
 
  
    the occurrence of unexpected manufacturing interruptions and
    outages, including those occurring as a result of production
    hazards or an interruption in the supply of electricity, salt or
    other raw materials; 
 
  
    failure to comply with financial covenants contained in our debt
    instruments; 
  
    inability to make scheduled payments on or refinance our
    indebtedness;
    loss of key customers or suppliers; 
  
    increased prices for raw materials, including electricity; 
  
    disruption of transportation or higher than expected
    transportation or logistics costs;
    the occurrence of accidents in the manufacturing, handling,
    storage or transportation of chlorine, including chemical spills
    or releases at our facilities or railcar accidents that result
    in a chlorine release;
    environmental costs and other expenditures in excess of those
    projected; 
  
    increased costs for litigation and other claims; 
  
    changes in laws and regulations inside or outside the United
    States; 
  
    uncertainty with respect to interest rates and fluctuations in
    currency exchange rates; 
  
    the occurrence of extraordinary events, such as Hurricanes
    Katrina and Rita, the attacks on the World Trade Center and the
    Pentagon that occurred on September 11, 2001, or the war in
    Iraq;
    our ability to obtain regulatory and Pioneer shareholder
    approval to consummate the merger with Olin Corporation and to
    satisfy the other closing conditions contained in the merger
    agreement; ii




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
    increases in costs and delays in the completion of the St.
    Gabriel project; and
    other factors discussed under Risk Factors or
    elsewhere in this prospectus and in the documents that we
    include or incorporate by reference into this prospectus,
    including our Annual Report on Form 10K/A for the fiscal
    year ended December 31, 2006 and our subsequent SEC filings.   INCORPORATION
    OF DOCUMENTS FILED WITH THE SEC    
    our Annual Report on
    Form 10-K/A
    for the year ended December 31, 2006, filed with the SEC on
    March 16, 2007;
    our Quarterly Report on
    Form 10-Q
    for the quarter ended March 31, 2007, filed with the SEC on
    May 9, 2007;  
    our Current Report on
    Form 8-K
    filed with the SEC on January 31, 2007 (Items 8.01 and
    9.01 only), March 22, 2007; March 28, 2007;
    May 22, 2007; and June 8, 2007;
    our Definitive Proxy Statement on Schedule 14A, filed with
    the SEC on April 19, 2007; and
    the description of our common stock contained in our
    registration statement on
    Form 8-A
    as filed with the SEC on June 16, 2003, and as such
    registration statement may be amended from time to time for the
    purpose of updating, changing or modifying the description of
    our common stock.  Form 8-K
  (713) 570-3200.
 iii




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PROSPECTUS
    SUMMARY  This summary highlights some important information about our
    business and about this offering. It does not include all of the
    information you should consider before deciding to purchase any
    notes or shares of our common stock. Please review this entire
    prospectus and the information incorporated herein by reference,
    including the risk factors section and our consolidated
    financial statements and related notes, before you decide to
    purchase any notes or shares of our common stock.
  Unless otherwise indicated, we, us,
    our and similar terms refer to Pioneer Companies,
    Inc. and its subsidiaries. We refer to chlorine and caustic soda
    collectively in this offering memorandum as
    chlor-alkali.
  Our
    Company
            (713) 570-3200. www.piona.com
  Pending
    Acquisition by Olin Corporation
 1




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Hart-Scott-Rodino
        The
    Offering
  We provide the following summary solely for your convenience.
    This summary is not a complete description of the notes. You
    should read the full text and more specific details contained
    elsewhere in this prospectus. For a more detailed description of
    the notes and our common stock issuable upon conversion of the
    notes, see the sections entitled Description of the
    Notes and Description of Capital Stock in this
    prospectus. With respect to the discussion of the terms of the
    notes on the cover page, in this section and in the section
    entitled Description of the Notes, the words
    we, our, us and
    Pioneer refer only to Pioneer Companies, Inc. and
    not any of its subsidiaries
  Issuer
    
    Pioneer Companies, Inc., a Delaware corporation.Securities Offered
    
    $120,000,000 aggregate principal amount of 2.75% convertible
    senior subordinated notes due 2027.Maturity Date
    
    March 1, 2027, unless earlier redeemed, repurchased or
    converted.
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Interest
    
    The notes bear interest at the rate of 2.75% per year, payable
    semi-annually, in arrears, on March 1 and September 1 of each
    year, commencing on September 1, 2007.Contingent Interest
    
    Beginning with the six-month interest period commencing
    March 1, 2014, we will pay contingent interest in cash
    during any six-month interest period in which the trading price
    of the notes for each of the five trading days ending on the
    second trading day immediately preceding the first day of the
    applicable six-month interest period equals or exceeds 120% of
    the principal amount of the notes.During any interest period when contingent interest shall be
    payable, the contingent interest payable per $1,000 principal
    amount of notes will equal 0.30% of the average trading price of
    $1,000 principal amount of the notes during the five trading
    days immediately preceding the first day of the applicable
    six-month interest period.Ranking
    
    The notes are our general unsecured senior subordinated
    obligations. Accordingly, they are: subordinate in right of payment to all of our
    existing and future senior indebtedness, but excluding
    indebtedness that expressly provides that it ranks equal or
    subordinate in right of payment to the notes; equal in right of payment to all of our existing and
    future senior subordinated indebtedness; and senior in right of payment to all of our future
    subordinated indebtedness.The notes also will be effectively junior in priority to our
    obligations under all secured indebtedness, including our
    revolving credit facility and any other secured obligations, in
    each case to the extent of the value of the assets securing such
    obligations. See Description of Other Indebtedness.The notes will also be effectively junior to all liabilities of
    our subsidiaries.As of March 31, 2007, Pioneer Companies, Inc. (excluding
    its subsidiaries) had only the $120 million of indebtedness
    under the notes. However, at such date, our subsidiaries had
    total senior indebtedness of approximately $77 million,
    consisting of $75 million of 10% Senior Secured Notes
    due 2008 and approximately $2 million of other
    indebtedness, and the ability to borrow under our revolving
    credit facility additional senior secured indebtedness of
    approximately $20.7 million, after reducing the amount of
    availability thereunder by the $9.3 million of letters of
    credit then outstanding. Obligations under our revolving credit
    facility are secured by liens on the accounts receivable and
    inventory of our subsidiaries. Pioneer Companies, Inc. also
    guaranteed the 10% Senior Secured Notes due 2008.As of March 31, 2007, our subsidiaries had approximately
    $140.4 million of other liabilities, including trade
    payables but excluding intercompany liabilities, all of which
    would have had a prior claim, ahead of the notes, on the assets
    of those subsidiaries. Neither we nor our subsidiaries are
    prohibited from incurring debt, including senior
 3




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indebtedness, under the indenture. On April 24, 2007, we
    redeemed the remaining $75 million principal balance of our
    10% Senior Secured Notes due 2008.For more information, see Description of Notes 
    Brief Description of the Notes.Conversion
    
    You may convert your notes into cash or, under certain
    circumstances, cash and shares of our common stock at any time
    on or prior to the trading day preceding January 1, 2014,
    subject to prior redemption or repurchase only during the
    specified periods under the following circumstances: during the five
    business-day
    period after any five consecutive
    trading-day
    period in which the trading price per $1,000 principal amount of
    notes for each day of such measurement period was less than 98%
    of the conversion value, which equals the product of the closing
    sale price of our common stock and the conversion rate then in
    effect; during any fiscal quarter after the fiscal quarter
    ending June 30, 2007, if the last reported sale price of
    our common stock for 20 or more trading days in a period of 30
    consecutive trading days ending on the last trading day of the
    immediately preceding fiscal quarter exceeds 120% of the
    applicable conversion price in effect on the last trading day of
    the immediately preceding fiscal quarter; if we call the notes for redemption; if a fundamental change occurs; or during prescribed periods upon the occurrence of
    certain corporate events described under Description of
    the Notes  Conversion Procedures 
    Conversion Upon Specified Corporate Transactions.On and after January 1, 2014, to (and including) the
    trading day preceding the maturity date, subject to prior
    redemption or repurchase, the notes will be convertible into
    cash and, if applicable, shares of our common stock regardless
    of the foregoing circumstances.The initial conversion rate is 28.3222 shares of common
    stock per $1,000 principal amount of notes, which represents an
    initial conversion price of approximately $35.31 per share,
    subject to adjustment, as described under Description of
    Notes  Conversion Procedures  Conversion
    Rate Adjustments.Upon conversion, we will pay on the third VWAP trading day
    following the last VWAP trading day of such observation period,
    with respect to each VWAP trading day of the related 20 VWAP
    trading day observation period, an amount in cash equal to the
    lesser of (i) $50.00 and (ii) the daily conversion
    value of the notes converted all calculated as described under
    Description of Notes  Conversion
    Rights  Settlement Upon Conversion. If the
    daily conversion value exceeds the principal portion of the
    converted notes on any VWAP trading day during the relevant 20
    VWAP
    trading-day
    observation period, in addition to paying the principal portion
    of the converted notes in cash for such VWAP trading day, we
    will also deliver, at our election, cash, shares of our common
    stock or a combination of cash and shares of our
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common stock in an amount equal to the excess of the daily
    conversion value over the principal portion of the converted
    notes for such VWAP trading day, all calculated as described
    under Description of Notes  Conversion
    Procedures  Settlement upon Conversion.If a fundamental change occurs prior to the maturity
    date, subject to certain limitations, we will increase the
    conversion rate for a holder who elects to convert its notes in
    connection with such fundamental change as described under
    Description of Notes  Determination of the
    Make-Whole Amount. No adjustment to the conversion rate
    will be made if the stock price is less than $27.16 or if the
    stock price exceeds $100.00 (in each case, subject to
    adjustment).Upon any conversion, subject to certain exceptions, you will not
    receive any cash payment representing accrued and unpaid
    interest (including contingent interest, if any) and additional
    interest, if any. See Description of Notes 
    Conversion Rights.Sinking Fund
    
    None.Optional Redemption by Pioneer
    
    We may not redeem the notes prior to March 6, 2014. We may
    redeem some or all of the notes for cash on or after
    March 6, 2014 at a redemption price equal to 100% of the
    principal amount of the notes, plus accrued and unpaid interest
    (including contingent interest, if any) and additional interest,
    if any, to, but not including, the redemption date.Repurchase at the Option of the Holder  Optional Put
    
    You may require us to repurchase in cash all or a portion of
    your notes on March 1, 2014, March 1, 2017 and
    March 1, 2022 at a repurchase price equal to 100% of the
    principal amount of the notes, plus accrued and unpaid interest
    (including contingent interest, if any) and additional interest,
    if any, to, but not including, the repurchase date.Repurchase at the Option of the Holder  Designated
    Event Put
    
    Subject to certain exceptions, if we undergo a designated
    event (as defined below under Description of
    Notes  Repurchase at the Option of the
    Holder  Designated Event Put) including a
    fundamental change, you will have the option to require us to
    repurchase all or any portion of your notes. The designated
    event repurchase price will be 100% of the principal amount of
    the notes to be purchased plus any accrued and unpaid interest
    (including contingent interest, if any) and additional interest,
    if any, to, but not including, the repurchase date.Events of Default
    
    If an event of default on the notes occurs, the principal amount
    of the notes, plus accrued and unpaid interest (including
    contingent interest, if any) and additional interest, if any,
    may be declared immediately due and payable, subject to certain
    conditions set forth in the indenture. These amounts
    automatically become due and payable in the case of certain
    types of bankruptcy or insolvency events of default involving us.Use of Proceeds
    
    We will not receive any of the proceeds upon resale of the notes
    or the common stock by any selling securityholder.
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Registration Rights
    
    Pursuant to a registration rights agreement we have entered into
    with the initial purchasers of the notes, we have filed a shelf
    registration statement, of which this prospectus is a part, with
    the SEC relating to the resale of the notes and common stock
    issuable upon conversion of the notes. We also have agreed to
    use our reasonable best efforts to keep the shelf registration
    statement effective until the earliest of: the date when all securities covered by the
    registration statement have been sold; the date when all of the notes and common stock
    issuable upon conversion have been sold pursuant to
    Rule 144 under the Securities Act; the expiration of the applicable holding period with
    respect to the notes and the common stock issuable upon
    conversion of the notes under Rule 144(k) under the
    Securities Act, or any successor provision; and the date when all of the notes and common stock
    issuable upon conversion cease to be outstanding.We are required to pay the holder of the notes additional
    interest on the notes if we fail to keep such registration
    statement effective during, the time periods specified above.
    See Description of the Notes  Registration
    Rights.No Prior Market; The
    PORTALSM
    Market
    
    The notes will not be listed on any securities exchange or
    included in any automated quotation system. The notes initially
    sold to qualified institutional buyers are eligible for trading
    in The
    PORTALSM
    Market. However, the notes resold pursuant to this prospectus
    will no longer be eligible for trading in The
    PORTALSM
    Market. An active or liquid market may not develop for the notes.Nasdaq Global Market Symbol for Our Common Stock
    
    Our common stock is listed on the Nasdaq Global Market under the
    symbol PONR.United States Federal Income Tax Considerations
    
    We and each holder of notes will agree to treat the notes, for
    United States federal income tax purposes, as debt instruments
    that are subject to the Treasury regulations that govern
    contingent payment debt instruments and to be bound by our
    application of such regulations to the notes, including our
    determination that the rate at which interest will be deemed to
    accrue for United States federal income tax purposes will be
    8.50% compounded semi-annually. Accordingly, each holder will
    recognize taxable income significantly in excess of cash
    received while the notes are outstanding. In addition, a United
    States Holder will recognize ordinary income upon a sale,
    exchange, conversion, redemption, or repurchase of the notes at
    a gain. See Certain United States Federal Income Tax
    Considerations.  Risk
    Factors
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Ratio of
    Earnings to Fixed Charges
    Three MonthsEnded March 31,


Year Ended December 31,2007


2006


2005


2004


2003


2002Ratio of Earnings to Fixed Charges


4.39
x


7.07
x


4.90
x


1.04
x


1.63
x



*     *
    
    Our earnings were insufficient to cover our fixed charges by
    $5.5 million for the year ended December 31, 2002.
 7




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RISK
    FACTORS  The following risk factors should be carefully considered in
    conjunction with the other information included in this
    prospectus and the documents incorporated herein by reference
    before purchasing any notes or shares of our common stock,
    including those set forth under Item 1A of our Annual
    Report on
    Form 10-K/A
    for the fiscal year ended December 31, 2006. The risks
    described below are not the only risks facing us. Additional
    risks and uncertainties not currently known to us or that we
    currently deem to be immaterial may also materially and
    adversely affect our business operations. The risks described in
    this section and included or incorporated by reference in this
    prospectus could cause our actual results to differ materially
    from those anticipated.
  Risks
    Related to Our Business
  For a
    discussion of specific risks relating to our business, see
    Item 1A. Risk Factors in our Annual Report on
    Form 10-K/A
    for the fiscal year ended December 31, 2006, which is
    incorporated herein by reference.
  Risks
    Related to Our Merger with Olin Corporation
  Failure
    to complete the merger with Olin Corporation could materially
    and adversely affect our results of operations and our stock
    price.
    
    the market price of our common stock may decline to the extent
    that the current market price includes a market assumption that
    the merger will be completed;
    we will remain liable for significant transaction costs,
    including legal, accounting, financial advisory and other costs
    relating to the merger;
    we may experience a negative reaction to the termination of the
    merger from our customers, employees and suppliers which may
    adversely impact future operating results; and
    under some circumstances, we may have to pay a termination fee
    to Olin in the amount of approximately $15.6 million.    Obtaining
    required approvals and satisfying closing conditions or other
    developments may delay or prevent completion of the
    merger.
    
    approval by our stockholders of the merger agreement;
    the absence of any law or order prohibiting the completion of
    the merger;
    expiration or termination of the
    Hart-Scott-Rodino
    waiting period (or any extension thereof); and
    obtaining (as applicable) necessary antitrust approvals under
    the laws of Canada and, as applicable, expiration or termination
    of any waiting periods under such laws. 8




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Diversion
    of management attention to the merger and employee uncertainty
    regarding the merger could adversely affect our business,
    financial condition and operating results.
    Risks
    Related to the Notes
  Our
    ability to generate the cash needed to service our debt
    obligations depends on certain factors beyond our
    control.
    We may
    not have the cash necessary to settle conversions of the notes
    or to repurchase the notes following the occurrence of specified
    corporate transactions.
   9




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Your
    right to receive payments on the notes is effectively junior to
    the right of lenders who have a security interest in certain of
    our assets to the extent of the value of those
    assets.
      Your
    right to receive payments on the notes will be junior to the
    rights of the lenders under our senior debt and any of our
    future senior indebtedness.
      Repayment
    of our debt, including the notes, is dependent, to a significant
    extent, on cash flow generated by our
    subsidiaries.
   10




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There
    are no restrictive covenants in the indenture for the notes
    relating to our ability to incur future indebtedness or complete
    other transactions. The indebtedness created by this offering,
    and any future indebtedness, could adversely affect our business
    and our ability to make full payment on the notes and may
    restrict our operating flexibility.
    
    require us to maintain any financial ratios or specified levels
    of net worth, revenues, income, cash flow or liquidity and,
    therefore, does not protect holders of the notes in the event
    that we experience significant adverse changes in our financial
    condition or results of operations;
    limit our ability or the ability of any of our subsidiaries to
    incur additional indebtedness that is junior to, pari passu
    with, or structurally senior in right of payment to the notes;
    restrict our ability to incur secured debt or to pledge our
    assets or those of our subsidiaries; or
    pay dividends or other distributions, make investments,
    repurchase equity or subordinated debt, or engage in
    transactions with affiliates.      
    limit cash flow available for general corporate purposes, such
    as acquisitions and capital expenditures, due to the ongoing
    cash flow requirements for debt service;
    limit our ability to obtain, or obtain on favorable terms,
    additional debt financing in the future for working capital or
    acquisitions;
    limit our flexibility in reacting to competitive and other
    changes in our industry and economic conditions generally;
    expose us to a risk that a substantial decrease in net cash
    flows due to an inability to monetize our interests in our
    companies, economic developments or adverse developments in our
    business could make it difficult to meet debt service
    requirements;
    increase our vulnerability to adverse economic and industry
    conditions; and
    expose us to risks inherent in interest rate fluctuations
    because of the variable interest rates on other debt
    instruments, which could result in higher interest expense in
    the event of increases in interest rates.    The
    conditional conversion feature of the notes may prevent the
    conversion of the notes prior to January 1,
    2014.
   11




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Holders
    may not receive any of our common stock upon
    conversion.
    The
    definition of a designated event requiring us to repurchase the
    notes is limited and therefore the market price of the notes may
    decline if we enter into a transaction that is not a designated
    event under the supplemental indenture.
        The
    net share settlement feature of the notes may have adverse
    consequences.
    
    result in holders receiving no shares of our common stock upon
    conversion or fewer shares of our common stock relative to the
    conversion value of the notes;
    reduce our liquidity because we will be required to pay the
    principal portion in cash;
    delay holders receipt of the proceeds upon
    conversion; and
    subject holders to market risk before receiving any shares upon
    conversion.  The
    issuance of additional stock in connection with acquisitions or
    otherwise will dilute all other stockholdings and could affect
    the price of our common stock and, therefore, the price of the
    notes.
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An
    active trading market for the notes may not develop. The failure
    of a market to develop for the notes could adversely affect the
    liquidity and value of holders notes.
  sm sm
    The
    market price of the notes could be significantly affected by the
    market price of our common stock, which may fluctuate
    significantly.
    
    fluctuations in our quarterly results of operations, cash flows,
    financial condition or those of other companies in our industry;
    the publics reaction to our press releases, announcements
    and filings with the SEC;
    additions or departures of key personnel;
    changes in financial estimates or recommendations by research
    analysts;
    changes in the amount of indebtedness we have outstanding;
    changes in the ratings of our notes, if rated, or other
    securities;
    changes in general conditions in the United States and
    international economy, financial markets or the industries in
    which we operate, including changes in regulatory requirements;
    significant contracts, acquisitions, dispositions, financings,
    joint marketing relationships, joint ventures or capital
    commitments by us or our competitors;
    developments related to significant claims or proceedings
    against us; and
    future sales of our equity or equity-linked securities.   13




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You
    may have to pay taxes with respect to distributions on our
    common stock that you do not receive.
  Non-U.S. Holders
  U.S.
    Holders will recognize income for U.S. federal income tax
    purposes significantly in excess of interest payments on the
    notes, and gain (if any) recognized on a disposition of notes
    will generally be taxed as ordinary income.
    Future
    sales of our common stock in the public market or the issuance
    of securities senior to our common stock could adversely affect
    the trading price of our common stock and the value of the notes
    and our ability to raise funds in new stock
    offerings.
    The
    additional shares by which the conversion rate will be increased
    for notes converted in connection with certain fundamental
    change transactions may not adequately compensate holders for
    the lost option time value of their notes as a result of any
    such fundamental change.
   14




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##### Table of Contents



As a
    holder of notes, you will not be entitled to any rights with
    respect to our common stock, but you will be subject to all
    changes made with respect to our common stock.
    The
    repurchase rights in the notes triggered by a designated event
    could discourage a potential acquiror.
    The
    conversion rate of the notes may not be adjusted for all
    dilutive events that may occur.
    The
    notes may not be rated or may receive a lower rating than
    anticipated.
    We
    have never paid dividends on our common stock and do not
    anticipate paying dividends in the foreseeable
    future.
   15




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##### Table of Contents



Provisions
    in our charter documents and Delaware law may delay or prevent
    an acquisition of our company.
     USE OF
    PROCEEDS   DESCRIPTION
    OF CAPITAL STOCK   
   
  Common
    Stock
  Voting
    Rights
      Liquidation
    Preferences
   16




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##### Table of Contents



Dividends
    Other
    Rights
    Modification
    
    the provisions establishing the terms of the common stock and
    preferred stock, as set forth in Article IV of the
    Certificate of Incorporation;
    the provisions regarding the management of our business by our
    board of directors, the number of directors constituting our
    board of directors and the applicability of the Certificate of
    Incorporation to directors elected by holders of any series of
    preferred stock, voting separately as a class, as set forth in
    Article VIII of the Certificate of Incorporation; or
    the provisions regarding the power of the board of directors to
    amend the Bylaws, as set forth in Article IX of the
    Certificate of Incorporation.  Trading
    Preferred
    Stock
      
    diluting the voting or other rights of the proposed acquiror or
    insurgent stockholder group;
    creating a substantial voting block in institutional or other
    hands that might undertake to support the position of the
    incumbent board; and
    effecting an acquisition that might complicate or preclude the
    change of control. 17




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##### Table of Contents



Provisions
    of Delaware Law and Pioneers Charter and Bylaws
  Limitation
    of Liability of Directors
    
    for any breach of the directors duty of loyalty to Pioneer
    or its stockholders;
    for acts or omissions not in good faith or which involve
    intentional misconduct or a knowing violation of law;
    for unlawful payments of dividends or unlawful stock repurchases
    or redemptions as provided in Section 174 of the General
    Corporation Law of the State of Delaware (the
    DGCL); or
    for any transaction from which the director derived an improper
    personal benefit.    Stockholder
    Action by Written Consent; Amendment of the Bylaws; Special
    Meetings of Stockholders
       18




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##### Table of Contents



Delaware
    Antitakeover Law
    Transfer
    Agent and Registrar
   DESCRIPTION
    OF OTHER INDEBTEDNESS  Our
    Revolving Credit Facility
    Form 10-K/A
  10%
    Senior Secured Notes due 2008
   DESCRIPTION
    OF THE NOTES        Brief
    Description of the Notes
    
    are limited to an aggregate principal amount of
    $120.0 million;
    bear interest at a rate of 2.75% per year, payable semi-annually
    in arrears, on March 1 and September 1 of each year, commencing
    on September 1, 2007;
    beginning with the six-month interest period commencing
    March 1, 2014, bear contingent interest in the
    circumstances described under  Contingent
    Interest;
    are our general unsecured senior subordinated obligations,
    ranking subordinate in right of payment to all of our existing
    and future senior indebtedness, structurally subordinate to all
    of the existing and future indebtedness and other liabilities of
    our subsidiaries, equal in right of payment with all of our
    existing and 19




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##### Table of Contents



future senior subordinated indebtedness and senior in right of
    payment to any of our future subordinated indebtedness, as set
    forth under  Subordination;  
    are convertible by you at any time prior to the trading day
    preceding January 1, 2014, only upon satisfaction of one of
    the conversion contingencies described below, into cash or,
    under certain circumstances, cash and shares of our common
    stock, in each case having an aggregate conversion value as
    described below. On and after January 1, 2014, to and
    including the close of business on the trading day preceding the
    maturity date, the notes will be convertible by you as provided
    in the prior sentence at any time without regard to any of the
    conversion contingencies. The initial conversion rate is
    28.3222 shares of our common stock per $1,000 principal
    amount of notes, which represents an initial conversion price of
    approximately $35.31 per share; and:  
    upon conversion, for each $1,000 principal amount of notes
    surrendered, we will deliver the conversion value to holders as
    follows: (1) an amount in cash equal to the lesser of
    (a) the aggregate conversion value of the notes to be
    converted and (b) $1,000, and (2) if the aggregate
    conversion value of the notes to be converted is greater than
    the principal return, an amount in cash, shares or combination
    thereof equal to such excess. See  Conversion
    Procedures  Settlement Upon Conversion;
    the conversion rate and the conversion price are subject to
    adjustment as described under  Conversion
    Procedures  Conversion Rate Adjustments;
    if you convert your notes in connection with a fundamental
    change, under certain circumstances, you will also receive
    accrued and unpaid interest to, but not including, the
    conversion date, and we will provide for a make whole amount by
    increasing, for the time period described herein, the applicable
    conversion rate for notes so surrendered for conversion by a
    number of additional shares determined as described under
     Determination of the Make Whole Amount;  
    be redeemable at our option in whole or in part beginning on
    March 6, 2014 at a redemption price payable in cash equal
    to 100% of the principal amount of the notes, plus accrued and
    unpaid interest (including contingent interest, if any) and
    additional interest, if any, to, but not including, the
    redemption date, as set forth under  Optional
    Redemption by Pioneer;
    be subject to repurchase by us, at your option, on March 1,
    2014, March 1, 2017 and March 1, 2022, at a repurchase
    price in cash equal to 100% of the principal amount of the
    notes, plus accrued and unpaid interest (including contingent
    interest, if any) and additional interest, if any, to, but not
    including, the repurchase date, as set forth under 
    Repurchase at the Option of the Holder  Optional
    Put;
    be subject to repurchase by us, at your option, if a fundamental
    change occurs, at a repurchase price in cash equal to 100% of
    the principal amount of the notes, plus accrued and unpaid
    interest (including contingent interest, if any) and additional
    interest, if any, to, but not including, the repurchase date. No
    make whole amount will be payable to a holder that elects to
    have its notes so repurchased; and
    be due on March 1, 2027, unless earlier converted, redeemed
    by us at our option or repurchased by us at your option.       20




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Payment
    at Maturity
    Interest
    
    we will not pay accrued interest (including contingent interest,
    if any) or additional interest, if any, on any notes when they
    are converted, except as described under  Conversion
    Rights; and
    on the maturity date we will pay accrued and unpaid interest
    only to the person to whom we pay the principal amount.    
    global notes to DTC in immediately available funds; and
    any certificated notes by check mailed to the holders of those
    notes; provided, however, at maturity, interest will be payable
    as described under  Payment at Maturity.  360-day 30-day
    Contingent
    Interest
       21




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##### Table of Contents




    the conversion rate then in effect; and
    the average closing sale price of our common stock over the five
    trading-day
    period ending on such determination date.      Conversion
    Rights
    
    upon satisfaction of a trading price condition;
    upon a fundamental change;
    if we call the notes for redemption;
    upon specified corporate transactions; or
    if the closing price of our common stock reaches a specified
    threshold.         22




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##### Table of Contents




    if you convert your notes in connection with a redemption;
    if you convert your notes in connection with a fundamental
    change and we have specified a fundamental change repurchase
    date that is after a record date and on or prior to the
    corresponding interest payment date;
    to the extent of any overdue interest (including overdue
    contingent interest, if any), if overdue interest (or overdue
    contingent interest) exists at the time of conversion with
    respect to such note; or
    in respect of any conversions that occur after the record date
    immediately preceding the maturity date.        Conversion
    Upon Satisfaction of Trading Price Condition
  trading-day
     23




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##### Table of Contents



Conversion
    Based on Common Stock Price
    Conversion
    Upon a Fundamental Change
    
    the conversion value, calculated as set forth below under
     Conversion Procedures  Settlement of
    Conversions in a Fundamental Change;
    under certain circumstances, we will provide for a make whole
    amount by increasing, for the period described herein, the
    applicable conversion rate for notes so surrendered for
    conversion by a number of additional shares determined as set
    forth under  Determination of the Make Whole
    Amount; and
    if you are entitled to a make whole amount, accrued and unpaid
    interest and additional interest, if any, to, but not including,
    the conversion date, which interest will be payable in cash.    Conversion
    Upon Specified Corporate Transactions
    
    distribute to all holders of our common stock rights or warrants
    entitling them to purchase, for a period of 45 calendar days or
    less, shares of our common stock at a price less than the
    average closing sale price of our common stock for the ten
    trading days preceding the declaration date for such
    distribution; or
    distribute to all holders of our common stock cash or other
    assets, debt securities or rights to purchase our securities,
    which distribution has a per share value exceeding 5% of the
    closing sale price of our common stock on the trading day
    preceding the declaration date for such distribution.   24




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##### Table of Contents



and/or
  Conversion
    Procedures
  Procedures
    to be Followed by a Holder
      
    complete and manually sign the conversion notice on the back of
    the note or facsimile of the conversion notice;
    deliver the completed conversion notice and the note to be
    converted to the conversion agent, which will initially be the
    trustee;
    if required, furnish appropriate endorsements and transfer
    documents;
    if required, pay funds equal to interest payable on the next
    interest payment date to which you are not entitled; and
    if required, pay all transfer or similar taxes, if any.      Settlement
    Upon Conversion
   25




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##### Table of Contents




    with respect to any conversion date occurring during the period
    beginning on the 25th scheduled trading day prior to the
    maturity date of the notes, the 20 consecutive VWAP
    trading-day
    period beginning on, and including, the 22nd scheduled
    trading day prior to the maturity date (or if such day is not a
    VWAP trading day, the next succeeding VWAP trading day); and
    in all other instances, the 20 consecutive VWAP
    trading-day
    period beginning on and including the third VWAP trading day
    after the conversion date.    
    cash equal to the lesser of (x) $50 and (y) the daily
    conversion value relating to such VWAP trading day (the amount
    determined pursuant to this clause being the principal
    portion); and
    if such daily conversion value exceeds $50, either (i) a
    number of shares (the maximum deliverable shares)
    equal to (A) the difference between such daily conversion
    value and $50, divided by (B) the daily VWAP of our common
    stock for such VWAP trading day, (ii) cash equal to the
    difference between such daily conversion value and $50 or
    (iii) any combination elected by us of shares and cash in
    an amount equal to such excess of the daily conversion value
    over $50.          half-hour
 26




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##### Table of Contents



Conversion
    Rate Adjustments
      CR ́

=

CRo

×

OS ́OSo
     CRo

=

the conversion rate in effect
    immediately prior to the ex-date for such dividend
    or distribution or the effective date of such share split or
    combination, as the case may be;CR ́

=

the conversion rate in effect
    immediately after the ex-date for such dividend or
    distribution or the effective date of such share split or
    combination, as the case may be;OSo

=

the number of shares of our common
    stock outstanding immediately prior to the ex-date
    for such dividend or distribution or the effective date of such
    share split or combination, as the case may be; andOS ́

=

the number of shares of our common
    stock that will be outstanding immediately after giving effect
    to such dividend or distribution or immediately after the
    effective date of such share split or combination, as the case
    may be.     CR ́

=

CRo

×

OSo + XOSo
    + Y
     CRo

=

the conversion rate in effect
    immediately prior to the ex-date for such
    distribution;CR ́

=

the conversion rate in effect
    immediately after the ex-date for such distribution;OSo

=

the number of shares of our common
    stock outstanding immediately prior to the ex-date
    for such distribution;X

=

the total number of shares of our
    common stock issuable pursuant to such rights or warrants; andY

=

the number of shares of our common
    stock equal to the aggregate price payable to exercise such
    rights or warrants divided by the average of the last reported
    sale prices of our common stock over the 10 consecutive
    trading-day period ending on the trading day immediately
    preceding the
    ex-date
    for such distribution.     
    dividends or distributions referred to in clause (1) or
    (2) above; 27




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##### Table of Contents




    dividends or distributions paid exclusively in cash; and
    spin-offs described below in this paragraph (3);    CR ́

=

CRo

×

SPoSPo
    − FMV
     CRo

=

the conversion rate in effect
    immediately prior to the ex-date for such
    distribution;CR ́

=

the conversion rate in effect
    immediately after the ex-date for such distribution;SPo

=

the average of the last reported
    sale prices of our common stock over the 10 consecutive
    trading-day period ending on the trading day immediately
    preceding the ex-date for such distribution; andFMV

=

the fair market value as
    determined by our board of directors of the shares of capital
    stock, evidences of indebtedness, assets or property distributed
    with respect to each outstanding share of our common stock on
    the ex-date for such distribution.     CR ́

=

CRo

×

FMVo + MPoMPo
     CRo

=

the conversion rate in effect
    immediately prior to the 10th trading day immediately
    following the effective date of the spin-off;CR ́

=

the conversion rate in effect
    immediately after the 10th trading day immediately
    following the effective date of the spin-off;FMVo

=

the average of the last reported
    sale prices of the capital stock or similar equity interest
    distributed to holders of our common stock applicable to one
    share of our common stock over the first 10 consecutive
    trading-day period immediately following, and including, the
    effective date of the spin-off; andMPo

=

the average of the last reported
    sale prices of our common stock over the first 10 consecutive
    trading-day period immediately following, and including, the
    effective date of the spin-off.       SPoCR ́

=

CRo

×SPo - C
   28




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##### Table of Contents



where,CRo

=

the conversion rate in effect
    immediately prior to the
    ex-date
    for such distribution;CR ́

=

the conversion rate in effect
    immediately after the ex-date for such distribution;SPo

=

the last reported sale price of
    our common stock on the trading day immediately preceding the
    ex-date
    for such distribution; andC

=

the amount in cash per share we
    distribute to holders of our common stock.     AC + (SP ́ x OS ́)CR ́

=

CRo

×OSo x SP ́     CRo

=

the conversion rate in effect on
    the date such tender or exchange offer expires;CR ́

=

the conversion rate in effect on
    the day next succeeding the date such tender or exchange offer
    expires;AC

=

the aggregate value of all cash
    and any other consideration as determined by our board of
    directors paid or payable for shares purchased in such tender or
    exchange offer;OSo

=

the number of shares of our common
    stock outstanding immediately prior to the date such tender or
    exchange offer expires;OS ́

=

the number of shares of our common
    stock outstanding immediately after the date such tender or
    exchange offer expires (after giving effect to such tender offer
    or exchange offer); andSP ́

=

the last reported sale price of
    our common stock on the trading day next succeeding the date
    such tender or exchange offer expires.     
    the tender offer or exchange offer is for an amount that
    increases the offerors ownership of Pioneer common stock
    to more than 25% of the total shares of common stock
    outstanding; and
    if the cash and value of any other consideration included in
    such payment per share exceeds the current market price per
    share on the business day immediately following the last date on
    which tenders or exchanges may be made pursuant to such tender
    or exchange offer.       29




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Determination
    of the Make Whole Amount
    trading-day
   30




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##### Table of Contents



Stock PriceEffective Date

$27.16


$31.00


$34.00


$37.00


$40.00


$45.00


$50.00


$60.00


$70.00


$80.00


$90.00


$100.00March 26, 2007


8.4967



8.1326



6.8954



5.9183



5.1278



4.1156



3.3678



2.3545



1.7192



1.3028



1.0056



0.7898March 1, 2008


8.4967



8.0294



6.7572



5.7535



4.9503



3.9311



3.1878



2.1945



1.5849



1.1903



0.9134



0.7138March 1, 2009


8.4967



7.7875



6.4807



5.4589



4.6503



3.6356



2.9078



1.9595



1.3921



1.0353



0.7878



0.6108March 1, 2010


8.4967



7.4552



6.1043



5.0643



4.2528



3.2534



2.5538



1.6695



1.1607



0.8516



0.6422



0.4958March 1, 2011


8.4967



7.0165



5.6102



4.5508



3.7378



2.7667



2.1078



1.3178



0.8907



0.6441



0.4822



0.3698March 1, 2012


8.4967



6.3810



4.8984



3.8102



3.0078



2.0934



1.5178



0.8861



0.5792



0.4153



0.3111



0.2398March 1, 2013


8.4967



5.4423



3.8219



2.7048



1.9428



1.1734



0.7598



0.3928



0.2507



0.1841



0.1411



0.1118March 1, 2014


8.4967



3.9359



1.6896



0.5346



0.1178



0.0000



0.0000



0.0000



0.0000



0.0000



0.0000



0.0000       
    If the stock price is between two stock price amounts on the
    table or the effective date is between two dates on the table,
    the number of additional shares will be determined by
    straight-line interpolation between the number of additional
    shares set forth for the higher and lower stock price amounts
    and the two dates, as applicable, based on a
    365-day year.
    If the stock price is in excess of $100.00 per share (subject to
    adjustment as described below), no additional shares will be
    issued.
    If the stock price is less than $27.16 per share (subject to
    adjustment as described below), no additional shares will be
    issued.      Treatment
    of Reference Property
    
    any reclassification of our common stock;
    a consolidation, merger or combination involving us; or
    a sale or conveyance to another person of all or substantially
    all of our property and assets, 31




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##### Table of Contents




    cash up to the aggregate principal portion thereof; and
    subject to our option to deliver cash, shares of our common
    stock or a combination of cash and shares of our common stock
    for the excess of the daily conversion value over the principal
    portion of the notes converted for each VWAP trading day during
    the specified 20 VWAP trading day observation period, as
    provided under  Settlement Upon
    Conversion above, in lieu of the shares of our common
    stock otherwise deliverable, the same type (in the same
    proportions) of consideration received by holders of our common
    stock in the relevant events (reference property).      Treatment
    of Rights
    Voluntary
    Increases of Conversion Rate
    Tax
    Effect
    Settlement
    of Conversions in a Fundamental Change
   32




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##### Table of Contents




    If the last VWAP trading day of the applicable observation
    period related to notes surrendered for conversion is prior to
    the third scheduled trading day preceding the effective date of
    the fundamental change, we will settle such conversion as
    described above under  Settlement Upon
    Conversion by delivering the amount of cash and shares of
    our common stock, if any, based on the conversion rate then in
    effect without regard to the number of additional shares to be
    added to the conversion rate as described above, on the third
    VWAP trading day immediately following the last VWAP trading day
    of the applicable observation period. In addition, as soon as
    practicable following the effective date of the fundamental
    change, we will deliver the increase in such amount of reference
    property deliverable in lieu of shares of our common stock, if
    any, as if the conversion rate had been increased by such number
    of additional shares during the related observation period and
    based upon the related daily VWAP prices during such observation
    period. If such increased amount results in an increase to the
    amount of cash to be paid to holders, we will pay such increase
    in cash, and if such increased amount results in an increase to
    the number of shares of our common stock, we will deliver such
    increase by delivering reference property based on such
    increased number of shares.
    If the last VWAP trading day of the applicable observation
    period related to notes surrendered for conversion is on or
    following the third scheduled trading day preceding the
    effective date of the fundamental change, we will settle such
    conversion as described above under  Settlement
    Upon Conversion based on the conversion rate as increased
    by the additional shares described above on the later to occur
    of (1) the effective date of the transaction and
    (2) third scheduled trading day immediately following the
    last day of the applicable observation period.  Optional
    Redemption by Pioneer
        
    that you have a right to convert the notes called for
    redemption, and the conversion rate then in effect; and
    the date on which your right to convert the notes called for
    redemption will expire.      Repurchase
    at the Option of the Holder
  Optional
    Put
   33




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##### Table of Contents




    if you hold certificated notes, the note certificate numbers;
    the portion of the principal amount of notes to be repurchased,
    which must be in $1,000 multiples; and
    that the notes are to be repurchased by us pursuant to the
    applicable provisions of the notes and the indenture.    
    if you hold certificated notes, the certificate numbers of the
    withdrawn notes;
    the principal amount of the withdrawn notes; and
    the principal amount, if any, which remains subject to the
    repurchase notice.      
    those notes will cease to be outstanding and interest (including
    contingent interest, if any) and additional interest, if any,
    will cease to accrue, whether or not book-entry transfer of the
    notes has been made or the notes have been delivered to the
    paying agent, as the case may be; and
    all other rights of the note holders will terminate, other than
    the right to receive the repurchase price upon delivery or
    transfer of the notes.    
    comply with the provisions of
    Rule 13e-4
    and any other tender offer rules under the Exchange Act that may
    be applicable at the time of the offer to repurchase the notes; 34




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##### Table of Contents




    file a Schedule TO or any other schedule required in
    connection with any offer by us to repurchase the notes; and
    comply with all other federal and state securities laws in
    connection with any offer by us to repurchase the notes.  Designated
    Event Put
            
    that does not result in a reclassification, conversion, exchange
    or cancellation of our outstanding common stock;
    pursuant to which the holders of our common stock immediately
    prior to the transaction have the entitlement to exercise,
    directly or indirectly, 50% or more of the voting power of all
    shares of capital stock entitled to vote generally in the
    election of directors of the continuing or surviving corporation
    immediately after the transaction; or
    which is effected solely to change our jurisdiction of
    incorporation and results in a reclassification, conversion or
    exchange of outstanding shares of our common stock solely into
    shares of common stock of the surviving entity; or       35




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##### Table of Contents




    the events causing a designated event and whether such
    designated event also constitutes a fundamental change;
    the date of the designated event;
    the last date on which a holder may exercise the repurchase
    right;
    the designated event repurchase price, if applicable;
    the designated event repurchase date;
    the name and address of the paying agent and the conversion
    agent, if applicable;
    the applicable conversion rate and any adjustments to the
    applicable conversion rate;
    that the notes with respect to which a designated event
    repurchase notice has been delivered by a holder may be
    converted only if the holder withdraws the designated event
    repurchase notice in accordance with the terms of the
    indenture; and
    the procedures that holders must follow to require us to
    repurchase their notes.      
    if certificated, the certificate numbers of your notes to be
    delivered for repurchase;
    the portion of the principal amount of notes to be repurchased,
    which must be $1,000 or an integral multiple thereof; and
    that the notes are to be repurchased by us pursuant to the
    applicable provisions of the notes and the indenture.    
    the principal amount of the withdrawn notes;
    if certificated notes have been issued, the certificate numbers
    of the withdrawn notes, or if not certificated, your notice must
    comply with appropriate DTC procedures; and
    the principal amount, if any, which remains subject to the
    repurchase notice.   36




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##### Table of Contents




    the notes will cease to be outstanding and interest will cease
    to accrue, whether or not book-entry transfer of the notes is
    made or whether or not the note is delivered to the paying
    agent; and
    all other rights of the holder will terminate other than the
    right to receive the designated event repurchase price and
    previously accrued and unpaid interest, if any, upon delivery or
    transfer of the notes.          Subordination
         37




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##### Table of Contents




    a default in the payment of designated senior indebtedness
    occurs and is continuing; or
    any other default occurs and is continuing with respect to
    designated senior indebtedness that permits holders of
    designated senior indebtedness to accelerate its maturity (or
    that would permit such holders to accelerate with the giving of
    notice or the passage of time or both), and the trustee receives
    a payment blockage notice from the holders of designated senior
    indebtedness.    
    in the case of a payment default, the date on which such default
    is cured or waived in writing by the holders of the designated
    senior indebtedness; and
    in the case of a non-payment default, the earlier of
    (a) the date on which such non-payment default is cured or
    waived in writing by the holders of the designated senior
    indebtedness or the designated senior indebtedness is paid in
    full in cash or (b) 179 calendar days after the receipt of
    the payment blockage notice.                
    to the extent that it may constitute indebtedness, any
    obligation for federal, state, local or other taxes; 38




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##### Table of Contents




    any indebtedness among or between Pioneer and any subsidiary of
    Pioneer, unless and for so long as such indebtedness has been
    pledged to secure obligations to a third party;
    to the extent that it may constitute indebtedness, any
    obligation in respect of any trade payable incurred for the
    purchase of goods or materials, or for services obtained in the
    ordinary course of business;
    indebtedness evidenced by the notes;
    indebtedness of such person that is expressly subordinate or
    junior in right of payment to any other indebtedness of such
    person;
    to the extent that it may constitute indebtedness, any
    obligation owing under leases (other than capital lease
    obligations) or management agreements; and
    any obligation that by operation of law is subordinate to any
    general unsecured obligations of such person.  Limitation
    on Layering
    Consolidation,
    Merger and Sale of Assets by Pioneer
    
    either (a) we are the continuing corporation or
    (b) the resulting, surviving or transferee person (if other
    than us) is a corporation or limited liability company organized
    and existing under the laws of the United States, any state
    thereof or the District of Columbia and such person assumes, by
    a supplemental indenture in a form reasonably satisfactory to
    the trustee, and a supplemental agreement, all of our
    obligations under the notes, the indenture and the registration
    rights agreement;
    immediately after giving effect to such transaction, no default
    or event of default has occurred and is continuing; and
    we have delivered to the trustee certain certificates and
    opinions of counsel if so requested by the trustee.       39




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##### Table of Contents



Events of
    Default; Notice and Waiver
    
    we fail to pay any interest (including contingent interest, if
    any) and additional interest, if any, on the notes when due and
    such failure continues for a period of 30 calendar days, whether
    or not the payment is prohibited by the subordination provisions
    of the indenture;
    we fail to pay principal of the notes when due at maturity, or
    we fail to pay the redemption price or repurchase price, in
    respect of any note when due, whether or not the payment is
    prohibited by the subordination provisions of the indenture;
    upon conversion of any note, we fail to deliver the conversion
    value when due, whether due in cash or cash and shares of common
    stock, as the case may be, and such failure continues for a
    period of 5 days thereafter;
    we fail to provide notice of the occurrence of a designated
    event on a timely basis;
    we fail to perform or observe any other term, covenant or
    agreement in the notes or the indenture for a period of 60
    calendar days after written notice of such failure is given to
    us by the trustee or to us and the trustee by the holders of at
    least 25% in aggregate principal amount of the notes then
    outstanding;
    we fail to pay principal of our indebtedness for borrowed money
    in an aggregate amount of $20 million or more when due upon
    acceleration thereof, and such indebtedness is not discharged,
    or such acceleration is not rescinded, stayed or annulled,
    within a period of 30 calendar days after written notice of such
    failure is given to us by the trustee or to us and the trustee
    by the holders of at least 25% in aggregate principal amount of
    the notes then outstanding;
    failure by us or any of our subsidiaries, within 30 days,
    to pay, bond or otherwise discharge any judgments or orders for
    the payment of money the total uninsured amount of which for us
    or any of our subsidiaries exceeds in the aggregate
    $20 million, which are not stayed on appeal; or
    certain events involving our bankruptcy, insolvency or
    reorganization.     40




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##### Table of Contents




    we have paid (or deposited with the trustee a sum sufficient to
    pay) (1) all overdue interest (including contingent
    interest, if any) and additional interest, if any, on all notes;
    (2) the principal amount of any notes that have become due
    otherwise than by such declaration of acceleration; (3) to
    the extent that payment of such interest is lawful, interest
    upon overdue interest (including contingent interest, if any)
    and additional interest, if any; and (4) all sums paid or
    advanced by the trustee under the indenture and the reasonable
    compensation, expenses, disbursements and advances of the
    trustee, its agents and counsel; and
    all events of default, other than the non-payment of the
    principal amount and any accrued and unpaid interest (including
    contingent interest, if any) and additional interest, if any,
    that have become due solely by such declaration of acceleration,
    have been cured or waived.      
    the holder has given the trustee written notice of an event of
    default;
    the holders of at least 25% in aggregate principal amount of
    outstanding notes make a written request to the trustee to
    pursue the remedy, and offer reasonable security or indemnity
    against any costs, liability or expense of the trustee;
    the trustee fails to comply with the request within 60 calendar
    days after receipt of the request and offer of
    indemnity; and
    the trustee does not receive an inconsistent direction from the
    holders of a majority in aggregate principal amount of
    outstanding notes.  Waiver
    
    our failure to pay principal of or interest (including
    contingent interest, if any) or additional interest, if any, on
    any note when due;
    our failure to convert any note as required by the indenture;
    our failure to pay the redemption price on the redemption date
    in connection with a redemption by Pioneer or the repurchase
    price on the repurchase date in connection with a holder
    exercising its repurchase rights; or
    our failure to comply with any of the provisions of the
    indenture that would require the consent of the holder of each
    outstanding note affected.  Modification
  Changes
    Requiring Approval of Each Affected Holder
    
    extend the maturity of any note; 41




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##### Table of Contents




    reduce the rate or extend the time for payment of interest
    (including contingent interest, if any) on any note;
    reduce the principal amount of any note;
    reduce any amount payable upon redemption or repurchase of any
    note;
    impair the right of a holder to institute suit for payment of
    any note;
    change the currency in which any note is payable;
    change our obligation to redeem any notes called for redemption
    on a redemption date in a manner adverse to the holders;
    change our obligation to repurchase any note at the option of
    the holder in a manner adverse to the holders;
    change our obligation to repurchase any note upon a fundamental
    change in a manner adverse to the holders;
    affect the right of a holder to convert any note or reduce the
    cash and number of shares of our common stock, if any, or any
    other property, if any, receivable upon conversion pursuant to
    the terms of the indenture;
    modify, in any material respect, the subordination provisions of
    the indenture in a manner adverse to the holders;
    subject to specified exceptions, modify certain provisions of
    the indenture relating to modification of the indenture or
    waiver under the indenture; or
    reduce the percentage of notes required for consent to any
    modification of the indenture that does not require the consent
    of each affected holder.  Changes
    Requiring Majority Approval
    Changes
    Requiring No Approval
    
    provide for conversion rights of holders of notes and our
    repurchase obligations in connection with a fundamental change
    in the event of any reclassification of our common stock, merger
    or consolidation, or sale, conveyance, transfer or lease of our
    property and assets substantially as an entity;
    secure the notes;
    provide for the assumption of our obligations to the holders of
    notes in the event of a merger or consolidation, or sale,
    conveyance, transfer or lease of our property and assets
    substantially as an entirety;
    add to our covenants for the benefit of the holders of notes;
    surrender any right or power conferred upon us;
    cure any ambiguity or correct or supplement any inconsistent or
    otherwise defective provision contained in the indenture;
    provided that such modification or amendment does not adversely
    affect the interests of the holders of notes in any material
    respect (it being understood that no modification or amendment
    to cure any ambiguity or correct or supplement any inconsistency
    or defect in the indenture made solely to conform the indenture
    to the description of notes contained in this prospectus will be
    deemed to adversely affect the interests of the holders of the
    notes);
    make any provision with respect to matters or questions arising
    under the indenture that we may deem necessary or desirable and
    that shall not be inconsistent with provisions of the indenture;
    provided that such 42




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##### Table of Contents



change or modification does not, in the good faith opinion of
    our board of directors, adversely affect the interests of the
    holders of notes in any material respect;  
    increase the conversion rate; provided, that the increase will
    not adversely affect the interests of the holders of notes;
    comply with the requirements of the SEC in order to effect or
    maintain the qualification of the indenture under the
    Trust Indenture Act;
    make any changes or modifications necessary in connection with
    the registration of the notes under the Securities Act as
    contemplated in the registration rights agreement; provided that
    such change or modification does not adversely affect the
    interests of the holders of notes in any material
    respect; and
    provide for a successor trustee.  Other
      Notes
    Not Entitled to Consent
    Form,
    Denomination and Registration
    
    in fully registered form;
    without interest coupons; and
    in denominations of $1,000 principal amount and integral
    multiples of $1,000.  Global
    Note, Book-Entry Form
       43




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##### Table of Contents




    not be entitled to have certificates registered in their names;
    not receive physical delivery of certificates in definitive
    registered form; and
    not be considered holders of the global note.    
    for any aspect of the records relating to, or payments made on
    account of, beneficial ownership interests in a global
    note; or
    for maintaining, supervising or reviewing any records relating
    to the beneficial ownership interests.      
    a limited purpose trust company organized under the laws of the
    State of New York, and a member of the Federal Reserve System;
    a clearing corporation within the meaning of the
    Uniform Commercial Code; and
    a clearing agency registered pursuant to the
    provisions of Section 17A of the Exchange Act.        Registration
    Rights
   44




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##### Table of Contents




    subject to certain of the civil liability provisions under the
    Securities Act in connection with the holders
    sales; and
    bound by the provisions of the registration rights agreement
    that are applicable to the holder, including indemnification
    rights and obligations.    
    the date when all of the notes and common stock issuable upon
    conversion of the notes of those holders that complete and
    deliver a selling securityholder election and questionnaire have
    been registered under the shelf registration statement and sold
    in accordance with it;
    the date when all of the notes and common stock issuable upon
    conversion of the notes have been sold pursuant to Rule 144
    under the Securities Act;
    the date on which the holders of the notes and the common stock
    issuable upon conversion of the notes are able to sell all such
    securities immediately pursuant to Rule 144(k) under the
    Securities Act; and
    the date when all of the notes and common stock issuable upon
    conversion of the notes cease to be outstanding.  calendar-day calendar-day calendar-day
      Repurchase
    and Cancellation
    Rule 144A
    Information Request
   45




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##### Table of Contents



Information
    Concerning the Trustee and Common Stock Transfer Agent and
    Registrar
      Governing
    Law
    Calculations
    in Respect of Notes
  l
 CERTAIN
    UNITED STATES FEDERAL INCOME TAX CONSIDERATIONS  TO ENSURE COMPLIANCE WITH TREASURY DEPARTMENT CIRCULAR 230,
    INVESTORS ARE HEREBY NOTIFIED THAT: (A) ANY DISCUSSION OF
    FEDERAL TAX ISSUES IN THIS PROSPECTUS IS NOT INTENDED OR WRITTEN
    TO BE RELIED UPON, AND CANNOT BE RELIED UPON, BY INVESTORS FOR
    THE PURPOSE OF AVOIDING PENALTIES THAT MAY BE IMPOSED ON
    INVESTORS UNDER THE INTERNAL REVENUE CODE; (B) SUCH
    DISCUSSION IS BEING USED IN CONNECTION WITH THE PROMOTION OR
    MARKETING (WITHIN THE MEANING OF CIRCULAR 230) BY THE
    ISSUER OF THE TRANSACTIONS OR MATTERS ADDRESSED HEREIN; AND
    (C) INVESTORS SHOULD SEEK ADVICE BASED ON THEIR PARTICULAR
    CIRCUMSTANCES FROM AN INDEPENDENT TAX ADVISOR.
    
    financial institutions,
    insurance companies,
    broker-dealers, 46




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##### Table of Contents




    tax-exempt organizations,
    certain former citizens or residents of the United States,
    persons that will hold the notes or the common stock received
    upon a conversion of the notes as part of a straddle, hedge,
    conversion, constructive sale, or other integrated transaction
    for United States federal income tax purposes, or
    U.S. Holders (as defined below) that have a functional
    currency other than the United States dollar.        
    an individual who is a citizen or resident of the United States,
    a corporation, partnership, or other entity created in, or
    organized under the law of, the United States or any state or
    political subdivision thereof,
    an estate the income of which is includible in gross income for
    United States federal income tax purposes regardless of its
    source, or
    a trust (A) the administration of which is subject to the
    primary supervision of a United States court and which has one
    or more United States persons who have the authority to control
    all substantial decisions of the trust, or (B) that was in
    existence on August 20, 1996, was treated as a United
    States person on the previous day, and elected to continue to be
    so treated.  Non-U.S. Holder.
  Classification
    of the Notes
    2002-31 2002-36, 2002-31 2002-36
 47




---



##### Table of Contents



U.S.
    Holders
  Interest Income.
          Adjustments to Interest Accruals on the
    Notes.
    Sale, Exchange, Conversion, Repurchase or
    Redemption.
 48




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##### Table of Contents



Constructive Dividends.
  Dividends on Common Stock. 120-day
  Disposition of Common Stock.
 49




---



##### Table of Contents



Non-U.S.
    Holders
  Notes. Non-U.S. Holder, Non-U.S. Holder Non-U.S. Holder Non-U.S. Holder Form W-8BEN Non-U.S. Holder Non-U.S. Holders
  Non-U.S. Holder Non-U.S. Holder Non-U.S. Holder Form W-8BEN Form W-8ECI Non-U.S. Holder
  Common Stock. Non-U.S. Holder Non-U.S. Holder Form W-8BEN Form W-8ECI Non-U.S. Holder
  Non-U.S. Holder Non-U.S. Holder Non-U.S. Holder Non-U.S. Holders
  Income Effectively Connected with a United States Trade or
    Business. Non-U.S. Holder Non-U.S. Holder, Non-U.S. Holder
  Information
    Reporting and Backup Withholding
  U.S. Holders.
 50




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##### Table of Contents



Non-U.S. Holders. Non-U.S. Holder Non-U.S. Holder Non-U.S. Holder. Non-U.S. Holder
 SELLING
    SECURITYHOLDERS            Number of


Common StockPercentage of Aggregate


Number of Shares


Shares of


Beneficially OwnedAmount of Notes


Principal Amount


of Common Stock


Common Stock


Following theName of Selling Securityholder

Offered Hereby


of Notes Outstanding


Owned(1)(2)


Offered Hereby(1)


Offering(3)Advent Convertible ARB Master(4)

$
1,457,000



1.2
%


41,265



41,265



0Alcon Laboratories(4)

$
238,000



*



6,740



6,740



0 51




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##### Table of Contents



Number of


Common StockPercentage of Aggregate


Number of Shares


Shares of


Beneficially OwnedAmount of Notes


Principal Amount


of Common Stock


Common Stock


Following theName of Selling Securityholder

Offered Hereby


of Notes Outstanding


Owned(1)(2)


Offered Hereby(1)


Offering(3)Alexandra Global Master
    Fund Ltd.(5)

$
5,000,000



4.2
%


141,611



141,611



0Arlington County Employees
    Retirement System(4)

$
342,000



*



9,686



9,686



0Arpeggio Fund(8)

$
1,700,000



1.4
%


48,147



48,147



0Bank of America Pension Plan(9)

$
2,032,000



1.6
%


57,550



57,550



0British Virgin Islands Social
    Security Board(4)

$
79,000



*



2,237



2,237



0Canyon Balanced Equity
    Master Fund, Ltd.(10)(11)

$
210,000



*



133,017



5,947



127,070Canyon Value Realization Fund,
    L.P.(10)(11)

$
435,000



*



204,835



12,320



192,515Canyon Value Realization
    MAC 18 Ltd.(10)(11)

$
55,000



*



26,667



1,557



25,110Citadel Equity Fund,
    Ltd. (12)(13)

$
18,250,000



15.2
%


516,880



516,880



0City University of New York(4)

$
68,000



*



1,925



1,925



0CNH CA Master Account, L.P.(14)

$
500,000



*



14,161



14,161



0CSV Fund(8)

$
1,000,000



*



28,322



28,322



0DBAG London (15)(16)

$
7,768,000



6.5
%


220,006



220,006



0CBARB, a segregated account of
    Geode Capital Master Fund Ltd.(17)

$
6,500,000



5.4
%


184,094



184,094



0Encore Fund(8)

$
1,000,000



*



28,322



28,322



0Fortissimo Fund(8)

$
500,000



*



14,161



14,161



0GMIMCO Trust(4)

$
875,000



*



24,781



24,781



0Grace Convertible Arbitrage Fund,
    Ltd.(18)

$
2,500,000



2.1
%


70,805



70,805



0Grady Hospital Foundation(4)

$
65,000



*



1,840



1,840



0Highbridge Convertible Arbitrage
    Master Fund, L.P. (6)

$
525,000



*



14,869



14,869



0Highbridge International LLC (7)

$
2,975,000



2.5
%


84,258



84,258



0HFR CA Opportunity Master Trust(4)

$
61,000



*



1,727



1,727



0IMF Converts(8)

$
2,200,000



1.8
%


62,308



62,308



0Institutional Benchmark Series in
    respect of Centaur Series(10)(11)

$
20,000



*



8,941



566



8,375JMG Triton Offshore Fund, Ltd.(19)

$
500,000



*



14,161



14,161



0Luxor/Canyon Value Realization
    Fund Ltd.(10)(11)

$
50,000



*



22,341



1,416



20,925Lyxor Master Trust Fund(4)

$
47,000



*



1,331



1,331



0Morgan Stanley Convertible
    Securities Trust (15)(20)

$
340,000



*



9,629



9,629



0Occidental Petroleum Corporation(4)

$
158,000



*



4,474



4,474



0 
 52




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##### Table of Contents



Number of


Common StockPercentage of Aggregate


Number of Shares


Shares of


Beneficially OwnedAmount of Notes


Principal Amount


of Common Stock


Common Stock


Following theName of Selling Securityholder

Offered Hereby


of Notes Outstanding


Owned(1)(2)


Offered Hereby(1)


Offering(3)Peoples Benefit Life Insurance
    Company Teamsters(9)

$
5,083,000



4.2
%


143,961



143,961



0Pro Mutual(4)

$
432,000



*



12,235



12,235



0Redbourn Partners Ltd.(9)

$
3,050,000



2.5
%


86,382



86,382



0Rhapsody Fund(8)

$
3,600,000



3.0
%


101,959



101,959



0San Francisco City and County
    ERS(4)

$
678,000



*



19,202



19,202



0Satellite Convertible Arbitrage
    Master Fund LLC(21)

$
5,000,000



4.2
%


141,611



141,611



0The Canyon Value Realization Fund
    (Cayman), Ltd.(10)(11)

$
1,130,000



*



521,634



32,004



489,630UBS AG London FBO WCBP(22)

$
5,000,000



4.2
%


253,511



253,511



0Van Kampen Harbor Fund (15)(23)

$
660,000



*



18,692



18,692



0Vicis Capital Master Fund(24)

$
1,000,000



*



28,322



28,322



0Any other holders of notes or
    future transferees, pledges, donees, assignees, or successors of
    any such holders (25)(26)

$
36,917,000



30.1
%


1,045,570



1,045,570



0  
    *
    
    Represents less than 1% of the notes outstanding.(1)
    
    Assumes conversion of all of the holders notes at a
    conversion rate of 28.3222 shares of common stock per
    $1,000 principal amount at maturity of the notes. This
    conversion rate is subject to adjustment, however, as described
    under Description of Notes  Conversion
    Rights and Description of Notes 
    Determination of Make Whole Amount. As a result, the
    number of shares of common stock issuable upon conversion of the
    notes may increase or decrease in the future.(2)
    
    Includes shares of common stock issuable upon conversion of the
    notes in addition to any other shares of common stock identified
    to us by the selling securityholder as owned by it. See footnote
    (1).(3)
    
    Assumes sale, transfer or other disposition of all common stock
    issuable upon conversion of the Notes.(4)
    
    This security holder has advised us that voting and dispositive
    power with respect to the notes or our common stock held by this
    security holder is held by Advent Capital Management, LLC. Tracy
    V. Maitland is the President and Chief Investment Officer of
    Advent Capital Management, LLC.(5)
    
    Alexandra Investment Management, LLC, a Delaware limited
    liability company (Alexandra), serves as investment
    advisor to the selling securityholder, Alexandra Global Master
    Fund Ltd (Alexandra Global). By reason of such
    relationship, Alexandra may be deemed to share dispositive power
    or investment control over the securities stated as beneficially
    owned by Alexandra Global. Alexandra disclaims beneficial
    ownership of such securities. Mikhail A. Filimonov
    (Filimonov) is a managing member of Alexandra. By
    reason of such relationship, Filimonov may be deemed to share
    dispositive power or investment control over the shares of
    common stock stated as beneficially owned by Alexandra Global.
    Filimonov disclaims beneficial ownership of such securities. 
  (6)
    
    Highbridge Capital Management, LLC is the trading manager of
    Highbridge Convertible Arbitrage Master Fund, L.P. and has
    voting control and investment discretion over the securities
    held by Highbridge Convertible Arbitrage Master Fund, L.P. Glenn
    Dubin and Henry Swieca control Highbridge Capital Management,
    LLC and have voting control and investment discretion over the
    securities held by Highbridge Convertible Master Fund, L.P. Each
    of Highbridge Capital Management, LLC, Glenn Dubin and Henry
    Swieca disclaims beneficial ownership of the securities held by
    Highbridge Convertible Arbitrage Master Fund, L.P. 
 53




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##### Table of Contents



(7)
    
    Highbridge Capital Management, LLC is the trading manager of
    Highbridge International LLC and has voting control and
    investment discretion over the securities held by Highbridge
    International LLC. Glenn Dubin and Henry Swieca control
    Highbridge Capital Management, LLC and have voting control and
    investment discretion over the securities held by Highbridge
    International LLC. Each of Highbridge Capital Management, LLC,
    Glenn Dubin and Henry Swieca disclaims beneficial ownership of
    the securities held by Highbridge International LLC. 
 
  (8)
    
    This securityholder has advised us that voting and dispositive
    power with respect to the notes or our common stock held by this
    securityholder is held by Eric White, the trade Operations
    Specialist. 
 
  (9)
    
    Camden Asset Management has the voting and dispositive power of
    the securities held by this selling securityholder.
    Mr. Tomas Kirvaitis is the portfolio manager of this
    selling securityholder. 
 
  (10)
    
    The selling securityholder has indicated that Goldman Sachs is
    the registered holder of the registrable securities. 
 
  (11)
    
    Canyon Capital Advisors LLC acts as the investment advisor for
    the selling securityholder and has the power to direct
    investments held by the selling securityholder. The managing
    partners of Canyon Capital Advisors LLC are Joshua S. Friedman,
    Mitchell R. Julis and K. Robert Turner. The selling
    securityholder has informed us that (i) it is an affiliate
    of Canyon Partners Incorporated, a registered broker-dealer,
    (ii) it purchased the securities in the ordinary course of
    business, and (iii) at the time of purchase, the selling
    securityholder had no agreements or understanding, directly or
    indirectly, with any person to distribute the securities. The
    selling securityholder is an affiliate of a broker-dealer. The
    selling securityholder received the notes in the ordinary course
    of business and to our knowledge has not agreed, directly or
    indirectly, to engage in a distribution of the notes. 
 
  (12)
    
    The selling securityholder has indicated that Citadel Trading
    Group, LLC is the registered holder of the registrable
    securities. 
 
  (13)
    
    Citadel Limited Partnership (CLP) is the trading
    manager of Citadel Equity Fund ltd. and consequently has
    investment discretion over securities held by Citadel Equity
    Fund Ltd. Citadel Investment Group, L.L.C.
    (CIG) controls CLP. Kenneth C. Griffin control CIG
    and therefore has ultimate investment discretion over securities
    held by Citadel Equity Fund ltd. CLP, CIG, and Mr. Griffin
    each disclaim ownership of the shares held by Citadel Equity
    Fund Ltd. 
 
  (14)
    
    CNH Partners, LLC is Investment Advisor of this selling
    securityholder and has sole dispositive power over the notes and
    sole dispositive and voting power over the common stock
    underlying the notes held by this selling securityholder.
    Investment principals for the Advisor are Robert Krail, Mark
    Mitchell and Todd Pulvino. 
 
  (15)
    
    The selling securityholder has indicated that Cede &
    Company is the registered holder of the registrable securities. 
 
  (16)
    
    Patrick Corrigan shares voting power and investment control over
    these securities. The selling securityholder is an affiliate of
    a registered broker-dealer. Due to this affiliation, the selling
    securityholder may be deemed a registered broker-dealer and
    therefore an underwriter within the meaning of
    Section 2(11) of the Securities Act. 
 
  (17)
    
    A segregated account of Geode Capital Master Fund Ltd., an
    open-ended exempted mutual fund company registered as a
    segregated accounts company under the laws of Bermuda. Phil
    Dumas has voting and investment control over these securities. 
 
  (18)
    
    This securityholder has advised us that voting and dispositive
    power with respect to these securities is held by Grace Brothers
    Management, LLC. The Managing Member of Grace Brothers
    Management, LLC and the natural person with voting and
    dispositve power with respect to these securities held by this
    securityholder is Michael Brailov. 
 
  (19)
    
    JMG Triton Offshore Fund, Ltd. (the Fund) is an
    international business company organized under the laws of the
    British Virgin Islands. The Funds investment manager is
    Pacific Assets Management LLC, a Delaware limited liability
    company (the Manager) that has voting and
    dispositive power over the Funds investments, including
    the registrable securities. The equity interest of the Manager
    are owned by Pacific Capital Management, Inc., a California
    corporation (Pacific) and Asset Holding Corp., a
    Delaware corporation. 
 54




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The equity interest of Pacific are owned by Messrs. Roger
    Richter, Jonathan M. Glasser and Daniel A. David.
    Messrs. Glaser and Richter have sole investment discretion
    over the Funds portfolio holdings. 
  (20)
    
    Morgan Stanley Investment Management is the investment advisor
    of the selling securityholder and exercises voting and
    dispositive power over these securities. The portfolio managers
    for the advisor are Ellen Gold and David McLaughlin. The selling
    securityholder has informed us that (i) it is an affiliate
    of a registered broker-dealer, (ii) it purchased the
    securities in the ordinary course of business, and (iii) at
    the time of purchase, the selling securityholder had no
    agreements or understandings, directly or indirectly, with any
    person to distribute the securities. 
 
  (21)
    
    The discretionary investment manager of this selling
    securityholder is Satellite Asset Management, L.P.
    (SAM). The controlling entity of SAM is Satellite
    Fund Management, LLC (SFM). The managing
    members of SFM are Lief Rosenblatt, Mark Sonnino and Gabe
    Nechamkin. SAM, SFM and each named individual disclaims
    beneficial ownership of the securities. 
 
  (22)
    
    Richard Simpson is the natural person with voting and
    dispositive power of these securities on behalf of this selling
    securityholder. The selling securityholder has informed us that
    (i) it is, or is an affiliate of, a registered
    broker-dealer, (ii) it purchased the securities in the
    ordinary course of business, and (iii) at the time of
    purchase, the selling securityholder had no agreements or
    understandings, directly or indirectly, with any person to
    distribute the securities. 
 
  (23)
    
    Van Kampen Asset Management is the investment advisor of the
    selling securityholder and exercises voting and dispositive
    power over these securities. The portfolio managers for the
    advisor are Ellen Gold and David McLaughlin. The selling
    securityholder has informed us that (i) it is an affiliate
    of a registered broker-dealer, (ii) it purchased the
    securities in the ordinary course of business, and (iii) at
    the time of purchase, the selling securityholder had no
    agreements or understandings, directly or indirectly, with any
    person to distribute the securities. 
 
  (24)
    
    Vicis Capital LLC is the investment manager of this selling
    securityholder. Shad Stastney, John Succo and Sky Lucas control
    Vicis Capital LLC. As such, Messrs. Stastney, Succo and
    Lucas are the natural persons who have voting and investment
    control of the securities being offered. Each of
    Messrs. Stastney, Succo and Lucas disclaims beneficial
    ownership of securities held by this securityholder. 
 
  (25)
    
    We are unable to provide the names of certain holders of notes
    and/or our common stock issuable upon conversion of the notes at
    this time, because they have not provided us with information
    and/or their notes are evidenced by a global note that has been
    deposited with DTC and registered in the name of
    Cede & Co., as DTCs nominee. Information
    concerning any such holders who are not listed in the above
    table will be set forth in post-effective amendments or
    prospectus supplements, as applicable, from time to time, if and
    when required. 
 
  (26)
    
    Assumes that all other holders of the notes do not beneficially
    own any of our common stock other than the shares issuable upon
    conversion of the notes. 
 PLAN OF
    DISTRIBUTION     55




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
    in market transactions;
    in privately negotiated transactions;
    through the writing of options;
    in a block trade in which a broker-dealer will attempt to sell a
    block of securities as agent but may position and resell a
    portion of the block as principal to facilitate the transaction;
    if we agree to it prior to the distribution, through one or more
    underwriters on a firm commitment or best-efforts basis;
    through broker-dealers, which may act as agents or principals;
    directly to one or more purchasers;
    through agents; or
    in any combination of the above or by any other legally
    available means.         56




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Rule 10b-5
        90-day calendar-day calendar-day
  LEGAL
    MATTERS    EXPERTS  Form 10-K/A
 57




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WHERE YOU
    CAN FIND MORE INFORMATION  1-800-SEC-0330. http://www.sec.gov. 001-09859.
  (713) 570-3200.
 58




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##### Table of Contents



PART II
  INFORMATION
    NOT REQUIRED IN PROSPECTUS
  ITEM 14.
    OTHER
    EXPENSES OF ISSUANCE AND DISTRIBUTION.    SEC registration fee

$
3,684Accounting fees and expenses

$
50,000Legal fees and expenses

$
75,000Printing expenses

$
30,000Trustees and transfer
    agents fees and expenses

$
30,000Miscellaneous

$
30,000Total

$
218,684   ITEM 15.
    INDEMNIFICATION
    OF DIRECTORS AND OFFICERS  Delaware
    General Corporation Law
       II-1




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##### Table of Contents



Fourth
    Amended and Restated Certificate of Incorporation
    Amended
    and Restated Bylaws
   II-2




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Indemnification
    Agreements
      Insurance
     II-3




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##### Table of Contents



ITEM 16.
    EXHIBITS.  
 Exhibit No.

Description2
.1*

Pioneer Companies, Inc. Amended
    Joint Plan of Reorganization under Chapter 11 of the United
    States Bankruptcy Code (incorporated by reference to
    Exhibit 2.1 to Pioneers Annual Report on
    Form 10-K
    for the fiscal year ended December 31, 2001).2
.2*

Order Approving Disclosure
    Statement, dated September 21, 2001 (incorporated by
    reference to Exhibit 2.2 to Pioneers Annual Report on
    Form 10-K
    for the fiscal year ended December 31, 2001).2
.3*

Order Confirming Joint Plan of
    Reorganization, dated November 28, 2001 (incorporated by
    reference to Exhibit 2.4 to Pioneers Current Report
    on
    Form 8-K
    filed on December 28, 2001).2
.4*

Asset Purchase and Sale Agreement
    dated December 22, 2005 between Mariana Properties, Inc.
    and Pioneer Americas LLC (incorporated by reference to
    Exhibit 10.1 to Pioneers Current Report on
    Form 8-K
    filed on January 5, 2006).2
.5*

Asset Purchase Agreement, dated as
    of September 22, 1997, between PCI Chemicals Canada Inc.
    (PCICC), PCI Carolina, Inc. and Pioneer Companies,
    Inc. and ICI Canada Inc., ICI Americas, Inc. and Imperial
    Chemical Industries PLC (incorporated by reference to
    Exhibit 2 to Pioneers Quarterly Report on
    Form 10-Q
    for the quarter ended September 30, 1997).2
.6*

First Amendment to Asset Purchase
    Agreement, dated as of October 31, 1997, between PCICC, PCI
    Carolina, Inc. and Pioneer Companies, Inc. and ICI Canada Inc.,
    ICI Americas, Inc. and Imperial Chemical Industries PLC
    (incorporated by reference to Exhibit 2 to Pioneers
    Current Report on
    Form 8-K
    filed on November 17, 1997).4
.1*

Fourth Amended and Restated
    Certificate of Incorporation of Pioneer Companies, Inc.
    (incorporated by reference to Exhibit 3.1 to Pioneers
    Annual Report on
    Form 10-K
    for the fiscal year ended December 31, 2001).4
.2*

Amended and Restated By-laws of
    Pioneer Companies, Inc. (incorporated by reference to
    Exhibit 3.2 to Pioneers Annual Report on
    Form 10-K
    for the fiscal year ended December 31, 2001).4
.3*

Specimen Pioneer Companies, Inc.
    Stock Certificate (incorporated by reference to Exhibit 4.1
    to Pioneers Annual Report on
    Form 10-K
    for the fiscal year ended December 31, 2001).4
.4*

Amended and Restated By-laws of
    Pioneer Companies, Inc. (incorporated by reference to
    Exhibit 3.2 to Pioneers Annual Report on
    Form 10-K
    for the fiscal year ended December 31, 2001).4
.5*

Specimen Pioneer Companies, Inc.
    Stock Certificate (incorporated by reference to Exhibit 4.1
    to Pioneers Annual Report on
    Form 10-K
    for the fiscal year ended December 31, 2001).4
.6*

Indenture, dated as of
    March 26, 2007, between Pioneer Companies, Inc. and Wells
    Fargo Bank, National Association, as Trustee (incorporated by
    reference to Exhibit 4.1 to Pioneers Current Report
    on
    Form 8-K
    filed on March 28, 2007).4
.7*

Form of 2.75% Convertible
    Senior Subordinated Note due 2027 (included in Exhibit 4.6
    and incorporated herein by reference).4
.8*

Registration Rights Agreement,
    dated as of March 26, 2007, among Pioneer Companies, Inc.,
    CIBC World Markets Corp., and CRT Capital Group LLC
    (incorporated by reference to Exhibit 4.2 to Pioneers
    Current Report on
    Form 8-K
    filed on March 28, 2007).5
.1**

Opinion of Locke
    Liddell & Sapp LLP with respect to the legality of the
    securities offered hereby12
.1**

Statement Regarding Computation of
    Ratio of Earnings to Fixed Charges23
.1

Consent of Deloitte &
    Touche LLP23
.2**

Consent of Locke
    Liddell & Sapp LLP (included in Exhibit 5.1)24
.1**

Powers of Attorney25
.1**

Statement of Eligibility of on
    Form T-1
    under the Trust Indenture Act of 1939, as amended, of Wells
    Fargo Bank, National Association, trustee under the Indenture  
    *
    
    Incorporated by reference as indicated. 
  **
    
    Previously filed. 
 II-4




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ITEM 17.
    UNDERTAKINGS            Provided, however
           II-5




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II-6




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##### Table of Contents



SIGNATURES
 
  Form S-3
 
    By:
    /s/  MICHAEL
    Y. MCGOVERN   Title:
    President and Chief Executive Officer 
  Form S-3
 
  
 Signature

Title

Date/s/  MICHAEL
    Y. MCGOVERN(Michael
    Y. McGovern)

President, Chief Executive Officer
    and Chairman of the Board of Directors

June 27, 2007/s/  GARY
    L. PITTMAN(Gary
    L. Pittman)

Senior Vice President, Chief
    Financial Officer, Treasurer and Secretary
    (Principal Financial Officer)

June 27, 2007*(Carl
    Monticone)

Vice President, Controller and
    Assistant Secretary
    (Principal Accounting Officer)

June 27, 2007*(Robert
    E. Allen)

Director

June 27, 2007*(Marvin
    E. Lesser)

Director

June 27, 2007*(Charles
    L. Mears)

Director

June 27, 2007*(David
    A. Scholes)

Senior Vice President,  Operations
    and Director

June 27, 2007*(Richard
    L. Urbanowski)

Director

June 27, 2007*By: /s/  GARY
    L. PITTMAN(Gary
    L. Pittman)
    Attorney-in-Fact



June 27, 2007  
 II-7




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##### Table of Contents



EXHIBIT INDEX
  
 Exhibit No.

Description2
.1*

Pioneer Companies, Inc. Amended
    Joint Plan of Reorganization under Chapter 11 of the United
    States Bankruptcy Code (incorporated by reference to
    Exhibit 2.1 to Pioneers Annual Report on
    Form 10-K
    for the fiscal year ended December 31, 2001).2
.2*

Order Approving Disclosure
    Statement, dated September 21, 2001 (incorporated by
    reference to Exhibit 2.2 to Pioneers Annual Report on
    Form 10-K
    for the fiscal year ended December 31, 2001).2
.3*

Order Confirming Joint Plan of
    Reorganization, dated November 28, 2001 (incorporated by
    reference to Exhibit 2.4 to Pioneers Current Report
    on
    Form 8-K
    filed on December 28, 2001).2
.4*

Asset Purchase and Sale Agreement
    dated December 22, 2005 between Mariana Properties, Inc.
    and Pioneer Americas LLC (incorporated by reference to
    Exhibit 10.1 to Pioneers Current Report on
    Form 8-K
    filed on January 5, 2006).2
.5*

Asset Purchase Agreement, dated as
    of September 22, 1997, between PCI Chemicals Canada Inc.
    (PCICC), PCI Carolina, Inc. and Pioneer Companies,
    Inc. and ICI Canada Inc., ICI Americas, Inc. and Imperial
    Chemical Industries PLC (incorporated by reference to
    Exhibit 2 to Pioneers Quarterly Report on
    Form 10-Q
    for the quarter ended September 30, 1997).2
.6*

First Amendment to Asset Purchase
    Agreement, dated as of October 31, 1997, between PCICC, PCI
    Carolina, Inc. and Pioneer Companies, Inc. and ICI Canada Inc.,
    ICI Americas, Inc. and Imperial Chemical Industries PLC
    (incorporated by reference to Exhibit 2 to Pioneers
    Current Report on
    Form 8-K
    filed on November 17, 1997).4
.1*

Fourth Amended and Restated
    Certificate of Incorporation of Pioneer Companies, Inc.
    (incorporated by reference to Exhibit 3.1 to Pioneers
    Annual Report on
    Form 10-K
    for the fiscal year ended December 31, 2001).4
.2*

Amended and Restated By-laws of
    Pioneer Companies, Inc. (incorporated by reference to
    Exhibit 3.2 to Pioneers Annual Report on
    Form 10-K
    for the fiscal year ended December 31, 2001).4
.3*

Specimen Pioneer Companies, Inc.
    Stock Certificate (incorporated by reference to Exhibit 4.1
    to Pioneers Annual Report on
    Form 10-K
    for the fiscal year ended December 31, 2001).4
.4*

Amended and Restated By-laws of
    Pioneer Companies, Inc. (incorporated by reference to
    Exhibit 3.2 to Pioneers Annual Report on
    Form 10-K
    for the fiscal year ended December 31, 2001).4
.5*

Specimen Pioneer Companies, Inc.
    Stock Certificate (incorporated by reference to Exhibit 4.1
    to Pioneers Annual Report on
    Form 10-K
    for the fiscal year ended December 31, 2001).4
.6*

Indenture, dated as of
    March 26, 2007, between Pioneer Companies, Inc. and Wells
    Fargo Bank, National Association, as Trustee (incorporated by
    reference to Exhibit 4.1 to Pioneers Current Report
    on
    Form 8-K
    filed on March 28, 2007).4
.7*

Form of 2.75% Convertible
    Senior Subordinated Note due 2027 (included in Exhibit 4.6
    and incorporated herein by reference).4
.8*

Registration Rights Agreement,
    dated as of March 26, 2007, among Pioneer Companies, Inc.,
    CIBC World Markets Corp., and CRT Capital Group LLC
    (incorporated by reference to Exhibit 4.2 to Pioneers
    Current Report on
    Form 8-K
    filed on March 28, 2007).5
.1**

Opinion of Locke
    Liddell & Sapp LLP with respect to the legality of the
    securities offered hereby12
.1**

Statement Regarding Computation of
    Ratio of Earnings to Fixed Charges23
.1

Consent of Deloitte &
    Touche LLP23
.2**

Consent of Locke
    Liddell & Sapp LLP (included in Exhibit 5.1)24
.1**

Powers of Attorney25
.1**

Statement of Eligibility of on
    Form T-1
    under the Trust Indenture Act of 1939, as amended, of Wells
    Fargo Bank, National Association, trustee under the Indenture  
   
  *
    
    Incorporated herein as indicated. 
 
  **
    
    Previously filed.