THIRD SUPPLEMENTAL INDENTURE

Exhibit 4.1

DOMTAR CORPORATION,

THE SUBSIDIARY GUARANTORS PARTY HERETO

and

THE BANK OF NEW YORK MELLON,

as Trustee

THIRD SUPPLEMENTAL INDENTURE

Dated as of June 9, 2009

10.75% Senior Notes due June 1, 2017

TABLE OF CONTENTS

THIS THIRD SUPPLEMENTAL INDENTURE (this “ Supplemental Indenture ”) dated as of June 9, 2009 is among DOMTAR CORPORATION, a Delaware corporation (together with its successors and assigns, the “ Company ”), the subsidiary guarantors listed on the signature pages hereto (each a “ Subsidiary Guarantor ,” and together, the “ Subsidiary Guarantors ”) under the Indenture referred to below and THE BANK OF NEW YORK MELLON (successor to The Bank of New York), a New York banking corporation, as Trustee (the “ Trustee ”) under the Indenture referred to below.

R E C I T A L S

WHEREAS, the Company has heretofore executed and delivered to the Trustee a Senior Indenture, dated as of November 19, 2007, among the Company, Domtar Paper Company, LLC and the Trustee (the “ Original Indenture ”), as supplemented by the Supplemental Indenture, dated as of February 15, 2008, among the Company, the subsidiary guarantors party thereto and the Trustee (the “ First Supplemental Indenture ”) and the Second Supplemental Indenture, dated as of February 20, 2008, among the Company, the subsidiary guarantors party thereto and the Trustee (the “ Second Supplemental Indenture ” and, together with this Supplemental Indenture, the Original Indenture and the First Supplemental Indenture, the “ Indenture ”), providing for the issuance from time to time of series of the Company’s Securities (as defined in the Original Indenture);

WHEREAS, Section 901(5) of the Original Indenture provides for the Company, the Subsidiary Guarantors and the Trustee to enter into an indenture supplemental to the Original Indenture to establish the form or terms of Securities of any series as permitted by Sections 201 or 301 of the Original Indenture;

WHEREAS, pursuant to Section 301 of the Original Indenture, the Company wishes to provide for the issuance of a new series of Securities to be known as its 10.75% Senior Notes due 2017, the form and terms of such Securities and the terms, provisions and conditions thereof to be set forth as provided in this Supplemental Indenture (the “ Notes ”);

WHEREAS, the Company has requested that the Trustee execute and deliver this Supplemental Indenture and all requirements necessary to make this Supplemental Indenture a valid, binding and enforceable instrument in accordance with its terms, and to make the Notes, when executed by the Company and authenticated and delivered by the Trustee, the valid, binding and enforceable obligations of the Company.

NOW, THEREFORE, in consideration of the covenants and agreements set forth herein and for other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, the Company, the Subsidiary Guarantors and the Trustee hereby agree as follows:

ARTICLE 1

D EFINITIONS

Section 1.01 . Relation to Original Indenture. This Supplemental Indenture constitutes an integral part of the Original Indenture.

Section 1.02 . Definition of Terms. For all purposes of this Supplemental Indenture:

(a) Capitalized terms used herein without definition shall have the meanings specified in the Original Indenture;

(b) a term defined anywhere in this Supplemental Indenture has the same meaning throughout;

(c) the singular includes the plural and vice versa;

(d) headings are for convenience of reference only and do not affect interpretation;

(e) the following terms have the meanings given to them in this Section 1.02(e):

Each of the following terms is defined in the section set forth opposite such term:

ARTICLE 2

THE N OTES

Section 2.01 . Designation . The Company hereby establishes a series of Securities for issuance under the Indenture designated the “10.75% Senior Notes due 2017.”

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Section 2.02 . Principal Amount. (a) The Notes shall be initially limited to an aggregate principal amount of $400,000,000.

(b) For all purposes of the Indenture, all Notes shall constitute one series of Securities and shall Act together as one series of Securities.

Section 2.03 . Payment of Interest; Record Date. The Regular Record Date for the interest payable on any Interest Payment Date of the Securities shall be the fifteenth day of the month preceding the Interest Payment Date.

Section 2.04 . Form of Notes; Global Form. (a) The Notes shall be substantially in the form of Exhibit A hereto. The terms and provisions contained in the form of Note set forth in Exhibit A shall constitute, and are hereby expressly made, a part of the Indenture.

Any of the Notes may have such letters, numbers or other marks of identification and such notations, legends, endorsements or changes as the officers executing the same may approve (execution thereof to be conclusive evidence of such approval) and as are not inconsistent with the provisions of the Indenture, or as may be required by the Depositary or with any rule or regulation of any securities exchange or automated quotation system on which the Notes may be listed, or to conform to usage, or to indicate any special limitations or restrictions to which any particular Notes are subject.

(b) So long as the Notes are eligible for book-entry settlement with the Depositary, or unless otherwise required by law, or otherwise contemplated by Section 305 of the Original Indenture, all of the Notes shall be represented by one or more Notes in global form registered in the name of the Depositary or the nominee of the Depositary (collectively, the “ Global Notes ”) and shall be deposited with the Depositary or the Trustee as custodian therefor. The transfer and exchange of beneficial interests in any such Global Note shall be effected through the Depositary in accordance with the Indenture and the applicable procedures of the Depositary. Except as provided in Section 305 of the Original Indenture, beneficial owners of a Global Note shall not be entitled to have certificates registered in their names, will not receive or be entitled to receive physical delivery of certificates in definitive form and will not be considered Holders of such Global Note.

Any Global Note shall represent such of the Outstanding Notes as shall be specified therein and shall represent the aggregate amount of Outstanding Notes from time to time endorsed thereon. Any endorsement of a Global Note to reflect the amount of any increase or decrease in the amount of Outstanding Notes represented thereby shall be made by the Trustee in such manner and upon instructions given by or through the Depositary in accordance with the Indenture. Payment of principal of and interest and premium, if any, on any Global Note shall be made to the Holder of such Note in accordance with the procedures of the Depositary.

Section 2.05. Restrictive Legends . Each Global Note shall bear the following legend on the face thereof:

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UNLESS THIS SECURITY IS PRESENTED BY AN AUTHORIZED REPRESENTATIVE OF THE DEPOSITORY TRUST COMPANY, A NEW YORK CORPORATION (“ DTC ”), TO THE COMPANY OR ITS AGENT FOR REGISTRATION OF TRANSFER, EXCHANGE OR PAYMENT, AND ANY SECURITY ISSUED IS REGISTERED IN THE NAME OF CEDE & CO. OR IN SUCH OTHER NAME AS REQUESTED BY AN AUTHORIZED REPRESENTATIVE OF DTC (AND ANY PAYMENT IS MADE TO CEDE & CO. OR TO SUCH OTHER ENTITY AS IS REQUESTED BY AN AUTHORIZED REPRESENTATIVE OF DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL INASMUCH AS THE REGISTERED OWNER HEREOF, CEDE & CO., HAS AN INTEREST HEREIN.

THIS SECURITY IS A GLOBAL SECURITY WITHIN THE MEANING OF THE INDENTURE HEREINAFTER REFERRED TO AND IS REGISTERED IN THE NAME OF DTC OR A NOMINEE THEREOF. THIS SECURITY MAY NOT BE EXCHANGED IN WHOLE OR IN PART FOR A SECURITY REGISTERED, AND NO TRANSFER OF THIS SECURITY IN WHOLE OR IN PART MAY BE REGISTERED, IN THE NAME OF ANY PERSON OTHER THAN DTC OR SUCH NOMINEE, EXCEPT IN THE LIMITED CIRCUMSTANCES DESCRIBED IN THE INDENTURE

Section 2.06. Registration, Registration of Transfer and Exchange . The Notes shall be subject to the provisions governing registration, registration of transfer and exchange in accordance with the terms and conditions set forth in Section 305 of the Original Indenture.

ARTICLE 3

R EDEMPTION OF THE N OTES

Section 3.01. Redemption by the Company . The Notes may be redeemed at the option of the Company on the terms and conditions set forth in the form of Note attached as Exhibit A hereto.

ARTICLE 4

D EFEASANCE

Section 4.01 . Defeasance. The Notes shall be subject to defeasance at the option of the Company in accordance with the terms and conditions set forth in Section 1301 of the Original Indenture.

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ARTICLE 5

M ISCELLANEOUS

Section 5.01 . Ratification of Indenture. The Original Indenture, as supplemented by this Supplemental Indenture, is in all respects ratified and confirmed, and this Supplemental Indenture shall be deemed part of the Original Indenture in the manner and to the extent herein and therein provided.

Section 5.02 . Trustee Not Responsible for Recitals. The recitals herein contained are made by the Company and not by the Trustee, and the Trustee assumes no responsibility for the correctness thereof. The Trustee makes no representation as to the validity or sufficiency of this Supplemental Indenture.

Section 5.03 . Governing Law. THIS SUPPLEMENTAL INDENTURE AND EACH NOTE SHALL BE GOVERNED BY AND CONSTRUED IN ACCORDANCE WITH THE LAWS OF THE STATE OF NEW YORK.

Section 5.04 . Separability. In case any one or more of the provisions contained in this Supplemental Indenture or in the Notes shall for any reason be held to be invalid, illegal or unenforceable in any respect, then, to the extent permitted by law, such invalidity, illegality or unenforceability shall not affect any other provisions of this Supplemental Indenture or of the Notes, but this Supplemental Indenture and the Notes shall be construed as if such invalid, illegal or unenforceable provision had never been contained herein or therein.

Section 5.05 . Counterparts. This Supplemental Indenture may be executed in any number of counterparts each of which shall be an original, but such counterparts shall together constitute but one and the same instrument.

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

Signature Page to Third Supplemental Indenture