First Supplemental Indenture


    Exhibit
      4.1

    


     

    


    
      
        

      



    


    


    


    


    PEOPLES
      ENERGY CORPORATION

    AND

    INTEGRYS
      ENERGY GROUP, INC.

     

    TO

     

    THE
      BANK OF
      NEW YORK TRUST COMPANY, N.A.,

     

    as
      Trustee

     

    


    


    _____________________________

    


    


    FIRST
      SUPPLEMENTAL INDENTURE

     

    


    Dated
      as of March
      5, 2007

    


    


    ______________________________

    


    


    


    


    


    


    
      
        

      



    


    
      
        
        

      

      
        
        

        
          

        

      

      
        
        

      

    

     

    


     


    FIRST
      SUPPLEMENTAL INDENTURE

     

    This
      First
      Supplemental Indenture, dated as of March 5, 2007 (this “First
      Supplemental Indenture”),
      by and among
      Peoples Energy Corporation, an Illinois corporation (“PEC”),
      Integrys Energy
      Group, Inc., a Wisconsin corporation (“Integrys”),
      and The Bank of
      New York Trust Company, N.A. (successor to Bank One Trust Company National
      Association) (the “Trustee”),
      as trustee
      under the Original Indenture (defined below). 

     

    WITNESSETH

    


    WHEREAS,
      PEC entered into
      that certain Indenture, dated as of January 18, 2001 (the “Original
      Indenture”),
      with the
      Trustee (as supplemented by this First Supplemental Indenture, the “Indenture”);


     

    WHEREAS,
      PEC currently has
      issued and Outstanding Securities under the Original Indenture in the principal
      amount of $325,000,000 senior unsecured 6.90% notes, due January 15, 2011 (the
      “Notes”);


     

    WHEREAS,
      pursuant to that
      certain Agreement and Plan of Merger dated as of July 8, 2006 (the “Merger
      Agreement”),
      by and among
      PEC, Integrys, and Wedge Acquisition Corp., a Delaware corporation and a
      wholly-owned subsidiary of Integrys (“Wedge”),
      PEC and Wedge
      have merged, with PEC as the surviving corporation (the “Merger”),
      and, as a
      result of the Merger, PEC is a wholly-owned subsidiary of Integrys;


     

    WHEREAS,
      Integrys desires
      to fully and unconditionally guarantee the due and punctual payment obligations
      of PEC with respect to the Notes as long as the Notes remain Outstanding;


     

    WHEREAS,
      Section 902 of
      the Original Indenture provides, among other things, that PEC, when authorized
      by a Board Resolution, and the Trustee, at any time and from time to time,
      may
      enter into an indenture supplemental to the Original Indenture with the consent
      of the Holders of not less than a majority in principal amount of the
      Outstanding Securities of each series affected by such supplemental indenture;
      and

     

    WHEREAS,
      the Holders of
      the Notes are the only Outstanding Securities affected by the First Supplemental
      Indenture, the Holders of not less than a majority in principal amount of the
      Notes have consented to the execution of this First Supplemental Indenture,
      the
      execution of this First Supplemental Indenture is authorized and permitted
      by
      Section 902 of the Original Indenture, all conditions precedent provided for
      in
      the Original Indenture relating to the execution of the First Supplemental
      Indenture have been complied with, and all things necessary to make this First
      Supplemental Indenture a valid agreement of PEC, Integrys, and the Trustee
      in
      accordance with its terms have been done; 

     

    NOW,
      THEREFORE,
      in consideration
      of the foregoing and for other good and valuable consideration, the receipt
      of
      which is hereby acknowledged, PEC, Integrys, and the Trustee mutually covenant
      and agree for the equal and ratable benefit of the Holders as
      follows:

     


    
      
        
        

      

      
        
        

        
          

        

      

      
        
        

      

    


    


     

    ARTICLE
      I
INTEGRYS GUARANTY 

     

    Section
      101.  Capitalized
      Terms.
      Capitalized terms
      used herein without definition shall have the meanings ascribed to them in
      the
      Original Indenture. 

     

    Section
      102.  Guaranty.
      Integrys does
      hereby fully and unconditionally guarantee for the benefit of the Holders and
      the Trustee (the “Guaranty”)
      (a) the due and
      punctual payment of the principal of, premium, if any, and interest on, all
      the
      Notes, whether at Stated Maturity, by declaration of acceleration, call for
      redemption or otherwise, the due and punctual payment of interest on overdue
      principal of, premium, if any, and interest on all of the Notes, if any, and
      the
      due and punctual performance of all other obligations of PEC to the Holders
      or
      the Trustee in accordance with the terms of the Indenture, and (b) in case
      of
      any extension of time of payment or renewal of any Notes or any such other
      obligations, that the same will be promptly paid in full when due or performed
      in accordance with the terms of the extension or renewal, whether at stated
      maturity, by acceleration, or otherwise. 

     

    In
      case of the
      failure of PEC to punctually make any such payment of principal, premium, if
      any, or interest, Integrys hereby agrees to cause any such payment to be made
      promptly when and as the same shall become due and payable, whether at Stated
      Maturity, by declaration of acceleration, call for redemption or otherwise,
      and
      as if such payment were made by PEC. 

     

    Integrys
      hereby
      agrees that its obligations under the Guaranty shall be as if it were principal
      debtor and not merely surety, and shall be absolute and unconditional,
      irrespective of, and shall be unaffected by, any invalidity, irregularity or
      unenforceability of any Note or the Indenture, any failure to enforce the
      provisions of any Note or the Indenture, or any waiver, modification or
      indulgence granted to PEC with respect thereto, by the Holder of any Note or
      the
      Trustee, or any other circumstance which may otherwise constitute a legal or
      equitable discharge of a surety or guarantor; provided, however, that,
      notwithstanding the foregoing, no such waiver, modification, or indulgence
      shall, without the consent of Integrys, increase the principal amount of a
      Note
      or the interest rate thereon or increase any premium payable upon redemption
      thereof. Integrys hereby waives diligence, presentment, demand of payment,
      filing of claims with a court in the event of a merger or bankruptcy of PEC,
      any
      right to require a proceeding first against PEC, protest or notice with respect
      to any Note or the indebtedness evidenced thereby or with respect to any sinking
      fund payment required pursuant to the terms of a Note issued under the
      Indenture, and all demands whatsoever, and covenants that the Guaranty will
      not
      be discharged with respect to any Note except by payment in full of the
      principal of (and premium, if any) and interest on such Note. The Guaranty
      shall
      constitute a guaranty of payment and not of collection and shall not be impaired
      by the failure to endorse evidence of the Guaranty on any Note.

     

    Integrys
      shall be
      subrogated to all rights of the Holder of a Note against PEC in respect of
      any
      amounts paid to such Holder by Integrys pursuant to the provisions of the
      Guaranty; provided, however, that Integrys shall not be entitled to enforce,
      or
      to receive any payments arising out of or based upon, such right of subrogation
      until the principal of (and premium, if any) and interest on all Notes have
      been
      paid in full. 

     


    
      
        
        

      

      
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    Section
      103.  Restrictions
      on Liens.

     

    After
      the date of
      the First Supplemental Indenture and so long as any Notes are Outstanding,
      Integrys will not pledge, mortgage, hypothecate or grant a security interest
      in,
      or permit any mortgage, pledge, security interest or other lien upon, any
      capital stock of any Integrys Subsidiary now or hereafter directly or indirectly
      owned by Integrys to secure any Indebtedness (hereinafter defined), without
      making effective provisions whereby the Outstanding Notes shall be (so long
      as
      such other Indebtedness shall be so secured) equally and ratably secured with
      any and all such other Indebtedness and any other indebtedness similarly
      entitled to be equally and ratably secured; provided, however, that this
      restriction shall not apply to nor prevent the creation or existence of (i)
      any
      mortgage, pledge, security interest, lien or encumbrance upon any such capital
      stock (A) created at the time of the acquisition of such capital stock by
      Integrys or within one year after such time to secure all or a portion of the
      purchase price for such capital stock or (B) existing thereon at the time of
      the
      acquisition thereof by Integrys (whether or not the obligations secured thereby
      are assumed by Integrys), or (ii) any extension, renewal or refunding of any
      mortgage, pledge, security interest, lien or encumbrance described in clause
      (i)
      above on capital stock of any Integrys Subsidiary theretofore subject thereto
      (or substantially the same capital stock) or any portion thereof. 

     

    For
      purposes of
      this Section 103, “Indebtedness”
means
      all
      indebtedness, whether or not represented by bonds, debentures, notes or other
      securities, created or assumed by Integrys or any Integrys Subsidiary for the
      repayment of money borrowed. All indebtedness for money borrowed secured by
      a
      lien upon property owned by Integrys or any Integrys Subsidiary and upon which
      indebtedness for money borrowed Integrys or such Integrys Subsidiary customarily
      pays interest, although Integrys or such Integrys Subsidiary has not assumed
      or
      become liable for the payment of such indebtedness for money borrowed, shall
      for
      purposes of this Section 103 be deemed to be indebtedness of Integrys or such
      Integrys Subsidiary. All indebtedness for money borrowed of others guaranteed
      as
      to payment of principal by Integrys or any Integrys Subsidiary or in effect
      guaranteed by Integrys or such Integrys Subsidiary through a contingent
      agreement to purchase such indebtedness for money borrowed shall be deemed
      for
      purposes of this Section 103 to be Indebtedness of Integrys or such
      Integrys Subsidiary, but no other contingent obligation of Integrys or any
      Integrys Subsidiary in respect of indebtedness for money borrowed or other
      obligations incurred by others shall for purposes of this Section 103 be deemed
      to be Indebtedness of Integrys or such Integrys Subsidiary. 

     

    In
      case Integrys or
      any Integrys Subsidiary shall propose to pledge, mortgage, hypothecate or grant
      a security interest in any capital stock of any Integrys Subsidiary owned by
      Integrys or such Integrys Subsidiary to secure any Indebtedness, other than
      as
      permitted by clauses (i) and (ii) in the second preceding paragraph, Integrys
      will prior thereto give written notice thereof to the Trustee, and Integrys
      will
      prior to or simultaneously with such pledge, mortgage, hypothecation or grant
      of
      security interest, by supplemental indenture executed to the Trustee (or to
      the
      extent legally necessary to another trustee or an additional or separate
      trustee), in form satisfactory to the Trustee, effectively secure (for so long
      as other Indebtedness shall be secured) all the Notes equally and ratably with
      such Indebtedness and with any other indebtedness for money borrowed similarly
      entitled to be equally and ratably secured.

     


    
      
        
        

      

      
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    For
      purposes of
      this Section 103, “Integrys
      Subsidiary”
means
      (i) any corporation of which more than 50% of the outstanding securities
      having ordinary voting power shall at the time be owned or controlled, directly
      or indirectly, by Integrys or by one or more other Integrys Subsidiaries or
      by
      Integrys and one or more other Integrys Subsidiaries, or (ii) any
      partnership, association, joint venture or similar business organization of
      which more than 50% of the ownership interests having ordinary voting power
      shall at the time be so owned or controlled.

     

    Section
      104.  Integrys
      May
      Consolidate.


     

    (1)  Nothing
      contained
      in the Original Indenture, this First Supplemental Indenture or any of the
      Notes
      shall prevent any consolidation or merger of Integrys with or into any other
      Person or Persons (whether or not affiliated with Integrys), or successive
      consolidations or mergers in which Integrys or its successor or successors
      shall
      be a party or parties, or shall prevent any conveyance or transfer of the
      properties and assets of Integrys as an entirety or substantially as an entirety
      to any other Person (whether or not affiliated with Integrys) lawfully entitled
      to acquire the same; provided,
      however,
      and Integrys
      hereby covenants and agrees, that upon any such consolidation, merger,
      conveyance or transfer, (i) the obligations of Integrys as set forth in Section
      102 herein shall be expressly assumed by a supplemental indenture, in form
      reasonably satisfactory to the Trustee, executed and delivered to the Trustee
      by
      the Person (if other than Integrys) formed by such consolidation, or into which
      Integrys shall have been merged, or by the Person which shall have acquired
      such
      properties and assets and (ii) Integrys shall deliver to the Trustee an
      Officers’ Certificate and an Opinion of Counsel, each stating that such
      consolidation, merger, conveyance or transfer and, if a supplemental indenture
      is required in connection with such transaction, such supplemental indenture,
      comply with this Section and that all conditions precedent herein provided
      for
      relating to such transaction have been fulfilled. 

     

    (2)  Upon
      any
      consolidation of Integrys with, or merger of Integrys into, any other Person
      or
      any conveyance or transfer of the properties and assets of Integrys as an
      entirety or substantially as an entirety in accordance with this Section, the
      successor Person formed by such consolidation or into which Integrys is merged
      or to which such conveyance or transfer is made shall succeed to, and be
      substituted for, and may exercise every right and power of, Integrys under
      this
      First Supplemental Indenture and the Original Indenture with the same effect
      as
      if such successor Person had been named as Integrys herein, and thereafter
      the
      predecessor Person shall be relieved of all obligations and covenants under
      this
      First Supplemental Indenture, the Original Indenture and the Notes.

     

    Section
      105.  Sole
      Benefit.

     

    This
      Article I
      shall be for the sole benefit of the Notes and not for the benefit of any future
      series of Securities Outstanding under the Indenture unless Integrys agrees
      otherwise.

     

    ARTICLE
      II  

    AMENDMENTS
      AND OTHER TERMS

     

    Section
      201.  Miscellaneous
      Amendments.


     

     

    
      
        
        

      

      
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    (a)  Section
      101 of the Original Indenture is hereby amended by adding the following
      definition: 

     

    “‘Integrys’
      means Integrys
      Energy Group, Inc., a Wisconsin corporation.” 

     

    (b)  Each
      of the
      following definitions set forth in Section 101 of the Original Indenture are
      hereby amended in their entirety to read as follows:

     

    “‘Board
      of
      Directors’
      means the board of
      directors of PEC or Integrys (as applicable), or any duly authorized committee
      thereof.”

     

    “‘Board
      Resolution’ means
      a copy of a
      resolution certified by the Corporate Secretary or an Assistant Corporate
      Secretary of PEC or Integrys (as applicable), to have been duly adopted by
      the
      Board of Directors and to be in full force and effect on the date of such
      certification, and delivered to the Trustee.”

     

    “‘Officers’
      Certificate’
      means a
      certificate signed by the Chairman of the Board, the President, the Chief
      Financial Officer or a Vice President, and by the Treasurer, an Assistant
      Treasurer, the Controller, an Assistant Controller, the Corporate Secretary
      or
      an Assistant Corporate Secretary, of PEC or Integrys (as applicable), that
      complies with the requirements of Section 314(c) of the Trust Indenture Act
      and
      is delivered to the Trustee.”

     

    “‘Opinion
      of
      Counsel’
      means a written
      opinion of counsel, who may be counsel for PEC or Integrys (as applicable),
      and
      who shall be acceptable to the Trustee, that complies with the requirements
      of
      Section 314(c) of the Trust Indenture Act and Section 102 of this
      Indenture.”

     

    “‘Request’
      or
‘Order’
      means a written
      request or order signed in the name of PEC or Integrys (as applicable), by
      its
      Chairman of the Board, its Vice Chairman, its President or a Vice President,
      and
      by its Treasurer, an Assistant Treasurer, its Controller, an Assistant
      Controller, its Corporate Secretary or an Assistant Corporate Secretary, and
      delivered to the Trustee.”

     

    (c)  Section
      105 of the
      Original Indenture is hereby amended by deleting “or” after clause (1) thereof,
      by deleting the period after clause (2) thereof and inserting “, or” in its
      place and by adding the following clause (3):

     

    “Integrys
      by the
      Trustee or by any Holder shall be sufficient for every purpose hereunder (unless
      otherwise herein expressly provided) if in writing and mailed, first-class
      postage prepaid, to Integrys, addressed to it at 130 East Randolph Drive,
      Chicago,

     


    
      
        
        

      

      
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    Illinois,
      60601,
      Attention: Secretary, or at any other address previously furnished in writing
      to
      the Trustee by Integrys.”

     

    (d)  Section
      108 of the
      Original Indenture is hereby amended by adding the following after the word
      “control”:

     

    “Integrys
      will
      comply with Sections 701, 704, and 1009(a) hereof to the extent required by
      the
      Trust Indenture Act.”

     

    (e)  Section
      501(4) of
      the Original Indenture is hereby amended to read as follows:

     

    “(4)
      a default in
      the performance, or breach, of any covenant of PEC or Integrys in this Indenture
      (other than a covenant or warranty a default in performance of which or breach
      of which is elsewhere in this Section specifically dealt with or which has
      expressly been included in or pursuant to this Indenture solely for the benefit
      of one or more series of Securities other than that series), and continuance
      of
      such default or breach for a period of 90 days after there has been given,
      by
      registered or certified mail, to PEC or Integrys, as applicable, by the Trustee,
      or to PEC or Integrys, as applicable, and the Trustee by the Holders of at
      least
      33% in principal amount of the Outstanding Securities of that series, a written
      notice specifying such default or breach and requiring it to be remedied and
      stating that such notice is a ‘Notice of Default’ hereunder; or”

     

    (f)  Section
      704 of the
      Original Indenture is hereby amended to read as follows: 

     

    “(1)
      PEC, pursuant
      to Section 314(a) of the Trust Indenture Act, shall file with the Trustee,
      within 15 days after PEC is required to file the same with the Commission,
      copies of the annual reports and of the information, documents and other reports
      (or copies of such portions of any of the foregoing as the Commission may from
      time to time by rules and regulations prescribe) which PEC may be required
      to
      file with the Commission pursuant to Section 13 or Section 15(d) of the
      Securities Exchange Act of 1934, as amended; or, if PEC is not required to
      file
      information, documents or reports pursuant to either of said sections, then
      PEC
      shall file with the Trustee and the Commission, in accordance with rules and
      regulations prescribed from time to time by the Commission under the Trust
      Indenture Act, such of the supplementary and periodic information, documents
      and
      reports which may be required pursuant to Section 13 of the Securities Exchange
      Act of 1934, as amended, in respect of a security listed and registered on
      a
      national securities exchange as may be prescribed from time to time in such
      rules and regulations. 

     


    
      
        
        

      

      
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    (2)
      Integrys,
      pursuant to Section 314(a) of the Trust Indenture Act, shall file with the
      Trustee, within 15 days after Integrys is required to file the same with the
      Commission, copies of the annual reports and of the information, documents
      and
      other reports (or copies of such portions of any of the foregoing as the
      Commission may from time to time by rules and regulations prescribe) which
      Integrys may be required to file with the Commission pursuant to Section 13
      or
      Section 15(d) of the Securities Exchange Act of 1934, as amended; or, if
      Integrys is not required to file information, documents or reports pursuant
      to
      either of said sections, then Integrys shall file with the Trustee and the
      Commission, in accordance with rules and regulations prescribed from time to
      time by the Commission, such of the supplementary and periodic information,
      documents and reports which may be required pursuant to Section 13 of the
      Securities Exchange Act of 1934, as amended, in respect of a security listed
      and
      registered on a national securities exchange as may be prescribed from time
      to
      time in such rules and regulations. 

     

    (3)
      PEC and, to the
      extent required by the Trust Indenture Act, Integrys, shall file with the
      Trustee and the Commission, in accordance with rules and regulations prescribed
      from time to time by the Commission, such additional information, documents
      and
      reports with respect to compliance by PEC, or Integrys, as the case may be,
      with
      the conditions and covenants of this Indenture as may be required from time
      to
      time by such rules and regulations. 

     

    (4)
      PEC and, to the
      extent required by the Trust Indenture Act, Integrys, shall transmit, within
      30
      days after the filing thereof with the Trustee, to the Holders of Securities,
      in
      the manner and to the extent provided in Section 313(c) of the Trust Indenture
      Act, such summaries of any information, documents and reports required to be
      filed by PEC, or Integrys, as the case may be, pursuant to paragraphs (1),
      (2)
      and (3) of this Section as may be required by rules and regulations prescribed
      from time to time by the Commission.”

     

    (g)  Section
      901(1) of
      the Original Indenture is hereby amended to read as follows:

     

    “(1)
      to evidence
      the succession of another Corporation to PEC or Integrys, as the case may be,
      and the assumption by any such successor of the covenants of, respectively,
      PEC
      or Integrys herein and in the Securities and coupons; or”

     

    This
      Section 201 shall be for the sole benefit of the Notes and not for the
      benefit of any future series of Securities Outstanding under the Indenture
      unless Integrys agrees otherwise.

     


    
      
        
        

      

      
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    Section
      202.  No
      Recourse Against Others.
      No past, present
      or future director, officer, employee, incorporator, stockholder, partner or
      agent of Integrys shall have any liability for any obligations of PEC or
      Integrys under the Securities, the Original Indenture or this First Supplemental
      Indenture or for any claim based on, in respect of, or by reason of, such
      obligations or their creation. 

     

    Section
      203.  Provisions
      Binding on Successors.
      All the
      covenants, stipulations, premises and agreements made in this First Supplemental
      Indenture by PEC and Integrys shall bind their respective successors and assigns
      whether so expressed or not. 

     

    Section
      204.  Governing
      Law.
      This First
      Supplemental Indenture shall be deemed to be a contract made under the laws
      of
      the State of Illinois and for all purposes shall be construed in accordance
      with
      the laws of said state. 

     

    Section
      205.  Execution
      and
      Counterparts.
      This First
      Supplemental Indenture may be executed in any number of counterparts, each
      of
      which when so executed shall be deemed to be an original, but all such
      counterparts shall together constitute one and the same instrument.


     

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

     

    Section
      207.  The
      Trustee.
      The Trustee shall
      not be responsible in any manner whatsoever for or in respect of the validity
      or
      sufficiency of the First Supplemental Indenture or for or in respect of the
      recitals contained herein, all of which recitals are made solely by PEC and
      Integrys. All of the provisions contained in the Indenture in respect of the
      rights, privileges, immunities, powers, and duties of the Trustee shall be
      applicable in respect of this First Supplemental Indenture as fully and with
      like force and effect as though fully set forth in full herein. The Trustee,
      subject to the provisions of the Trust Indenture Act, enters into this First
      Supplemental Indenture in reliance on an Opinion of Counsel as provided by
      Section 903 of the Indenture, and makes no independent determination that this
      Supplemental Indenture is authorized or permitted by the Original
      Indenture.

     

    Section
      208.  Full
      Force and
      Effect.
      Except as
      expressly amended hereby, the Original Indenture shall remain in full force
      and
      effect in accordance with the provisions thereof on the date thereof.


     

    [signature
      page
      attached]


    
      
        
        

      

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

     

    


    
      	 	
              PEOPLES
                ENERGY CORPORATION

               

               

              By:
                /s/
                Bradley A. Johnson  

              Name: Bradley
                A.
                Johnson

              Title:
                 Treasurer

            
	
              Attest:

               

              /s/
                Peter
                H. Kauffman

              Name:
                Peter
                H. Kauffman

              Title:
                Secretary and Chief Governance Officer

            	 
	 	
              INTEGRYS
                ENERGY GROUP, INC.

               

               

              By:
                /s/
                Bradley A. Johnson  

              Name: Bradley
                A.
                Johnson

              Title:
                 Vice
                President and Treasurer

            
	
              Attest:

               

              /s/
                Peter
                H. Kauffman

              Name:
                Peter
                H. Kauffman

              Title:
                Secretary and Chief Governance Officer

            	 
	 	
              THE
                BANK OF
                NEW YORK TRUST COMPANY, N.A., as
                Trustee

               

               

              By:
                /s/
                Benita
                A. Vaughn  

              Name: Benita
                A.
                Vaughn

              Title:
                Vice
                President

            
	
               

            	 
	 	 


    

    


    


    
      
        
        

      

      
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