QuickLinks
 -- Click here to rapidly navigate through this document

 
 

EXHIBIT 4.2(z)    
  


NORTHWESTERN ENERGY, L.L.C.  


 AND  


 NORTHWESTERN CORPORATION  


 TO  


 THE BANK OF NEW YORK  


 Trustee  




SECOND SUPPLEMENTAL INDENTURE

(For Unsecured Subordinated Debt Securities

relating to Trust Securities)  


 Dated as of August 13, 2002  








        SECOND SUPPLEMENTAL INDENTURE, dated as of August 13, 2002 (this "Second Supplemental
Indenture"), among NORTHWESTERN ENERGY, L.L.C., a limited liability company duly organized and existing under the laws of the
State of Montana, formerly known as The Montana Power, L.L.C. and successor by merger to The Montana Power Company (the "Company"), having its principal
office at 40 East Broadway, Butte, Montana 59701, NORTHWESTERN CORPORATION, a corporation duly organized and existing under the laws of the State of
Delaware, having its principal office at 125 S. Dakota Avenue, Sioux Falls, South Dakota 57104 ("NOR"), and THE BANK OF NEW
YORK, a corporation duly organized and existing as a banking corporation under the laws of the State of New York, having its principal corporate trust office at 101 Barclay
Street, New York, New York 10286, as Trustee (the "Trustee"), supplementing the Indenture, dated as of November 1996, between The Montana Power
Company, predecessor to the Company, and the Trustee, as amended by the First Supplemental Indenture, dated as of February 13, 2002, between the Company (formerly known as The Montana Power,
L.L.C.) and the Trustee (as supplemented, the "Indenture"). 


RECITALS  


        WHEREAS, pursuant to a Unit Purchase Agreement, dated as of September 29, 2000, by and between NOR, Touch America Holdings, Inc. and The Montana
Power Company, on February 15, 2002, NOR acquired all the outstanding membership interests in the Company and the Company became a direct wholly-owned subsidiary of NOR; and 



        WHEREAS,
as of the date hereof, $67,010,325 aggregate principal amount of the Company's 8.45% Junior Subordinated Debentures due December 31, 2036 are the only Securities
Outstanding under the Indenture (the "QUIPS Debentures"); 


        WHEREAS,
NOR now desires to enter into this Second Supplemental Indenture to fully and unconditionally assume, on a joint and several basis with the Company, the Company's obligations
with respect to the Outstanding QUIPS Debentures and the performance of every covenant, obligation and agreement of the Company under the Indenture applicable to the Outstanding QUIPS Debentures to be
performed or observed as though each such covenant, obligation and agreement were applicable directly to NOR (substituting NOR for the Company for purposes of the Indenture), which assumption shall be
subject to all of the terms and conditions related to the QUIPS Debentures contained herein, in the Indenture and in the QUIPS Debentures, including, without limitation, the subordination of the
obligations so assumed to all Senior Indebtedness of NOR (substituting NOR for the Company for purposes of the definition of Senior Indebtedness) to the same extent as such QUIPS Debentures are
subordinated to all Senior Indebtedness of the Company, and which assumption shall remain in effect only for so long as any of the QUIPS Debentures, which are outstanding on the date hereof, shall
remain Outstanding; and 


        WHEREAS,
Section 1201(b) of the Indenture permits the parties thereto to enter into a supplemental indenture without the consent of Holders to add provisions to the Indenture for
the benefit of all Holders or for the benefit of the Holders of, or to remain in effect only so long as there shall be Outstanding, Securities of one or more specified series; and 


        WHEREAS,
the assumption by NOR of the obligations of the Company with respect to the QUIPS Debentures under the Indenture will benefit the Holders of the Outstanding QUIPS Debentures;
and 


        WHEREAS,
the Company and NOR have duly authorized the execution and delivery of this Second Supplemental Indenture pursuant to Section 1201(b) of the Indenture; and 


        WHEREAS,
the Company and NOR have requested the Trustee join with them in the execution of this Second Supplemental Indenture. 





 



        NOW,
THEREFORE, in consideration of the mutual covenants and agreements contained herein and for other good and valuable consideration, the receipt and sufficiency of which are hereby
acknowledged, the parties hereto, intending to be legally bound, hereby agree as follows: 


ARTICLE ONE  


 Additional Obligor.  


        Section 101.    As of the date hereof, NOR fully and unconditionally assumes, on a joint and several basis with the
Company, the due and punctual payment of the principal of and premium, if any, and interest, if any, on all Outstanding QUIPS Debentures and the performance of every covenant, obligation and agreement
of the Company under the Indenture applicable to the Outstanding QUIPS Debentures to
be performed or observed as though each such covenant, obligation and agreement were applicable directly to NOR (substituting NOR for the Company for purposes of the Indenture), which assumption shall
be subject to all of the terms and conditions related to the QUIPS Debentures contained herein, in the Indenture and in the QUIPS Debentures, including, without limitation, the subordination of such
obligations to all Senior Indebtedness of NOR (substituting NOR for the Company for purposes of the definition of Senior Indebtedness) to the same extent as such QUIPS Debentures are subordinated to
all Senior Indebtedness of the Company. The assumption contained in this Second Supplemental Indenture shall remain in effect only for so long as any of the QUIPS Debentures, which are Outstanding on
the date hereof, shall remain Outstanding. Notwithstanding the assumption contained in this Second Supplemental Indenture, the obligations of the Company to duly and punctually pay the principal of
and premium, if any, and interest, if any, on the Outstanding QUIPS Debentures and to perform its covenants, obligations and agreements on the part of the Company under the Indenture shall remain in
full force and effect, without diminution or derogation in any respect whatsoever. 


ARTICLE TWO  


 Rights of Parties Not Prejudiced.  


        Section 201.    Notwithstanding the foregoing, the assumption contained in this Second Supplemental Indenture shall be
without prejudice to any rights of each of the Company and NOR under the QUIPs Debentures, the Indenture and this Second Supplemental Indenture, including, without limitation, the right of each of the
Company and NOR to consolidate with or merge into any other corporation, or convey or otherwise transfer, or lease, its properties and assets substantially as an entirety to any Person, and to be
relieved from its obligations under the QUIPS Debenture, the Indenture and hereunder, as provided in Article Eleven of the Indenture. For the avoidance of doubt, the Company may consolidate with or
merge into NOR or convey or otherwise transfer, or lease, its properties and assets substantially as an entirety to NOR, and be relieved of its obligations under the QUIPS Debentures, the Indenture
and hereunder as provided in Article Eleven of the Indenture notwithstanding the fact that NOR has assumed the Company's obligations under the QUIPS Debentures and the Indenture pursuant to this
Second Supplemental Indenture, and such assumption hereunder is expressly subject to such right. 


ARTICLE THREE  


 Miscellaneous Provisions.  


        Section 301.    The terms defined in the Indenture shall, for all purposes of this Second Supplemental Indenture, have
the meaning specified in the Indenture. 


        Section 302.    The Trustee hereby accepts the trusts herein declared, provided, created or supplemented and agrees to
perform the same upon the terms and conditions herein and in the 


2





 




Indenture set forth; provided, however, that the Trustee shall not be responsible in any manner whatsoever for or in respect of the validity or
sufficiency of this Second Supplemental Indenture or for or in respect of the recitals contained herein, all of which recitals are made solely by the Company and NOR. 


        Section 303.    Each and every term and condition contained in this Second Supplemental Indenture shall apply to and form
part of the Indenture with the same force and effect as if the same were set forth in full with such omissions, variations and insertions, if any, as may be appropriate to make the same conform to the
provisions of this Second Supplemental Indenture and each and every term and condition contained in Article Nine of the Indenture shall apply to and form part of this Second Supplemental Indenture
with the same force and effect as if the same were set forth in full herein. 


        Section 304.    Whenever in this Second Supplemental Indenture any of the parties hereto is named or referred to, this
shall, subject to the provisions of the Indenture, be deemed to include the successors and assigns of such respective parties, and all the covenants and agreements in this Second Supplemental
Indenture contained by or on behalf of the Company, NOR or the Trustee shall, subject as aforesaid, bind and inure to the respective benefits of the respective successors and assigns of such parties,
whether so expressed or not. 


        Section 305.    Nothing in this Second Supplemental Indenture, expressed or implied, is intended, or shall be construed,
to confer upon, or to give to, any person, firm or corporation, other than the parties hereto and the Holders of the QUIPS Debentures Outstanding under the Indenture, as amended and supplemented, any
right, remedy or claim under or by reason of this Second Supplemental Indenture or any covenant, condition, stipulation, promise or agreement hereof, and all the covenants, conditions, stipulations,
promises and agreements in this Second Supplemental Indenture contained by or on behalf of respective parties shall be for the sole and exclusive benefit of the parties hereto, and of the Holders of
the QUIPS Debentures Outstanding under the Indenture. 


        Section 306.    This Second Supplemental Indenture may be executed in several counterparts, each of which shall be deemed
to be an original and all of which shall constitute but one and the same instrument. 


        Section 307.    Except as set forth in this Second Supplemental Indenture, all of the provisions of the Indenture remain
in full force and effect, unamended. 


        Section 308.    This Second Supplemental Indenture shall be governed by and construed in accordance with the laws of the
State of New York, except to the extent that the law of any other jurisdiction shall be mandatorily applicable. 


        Section 309.    In case any one or more of the provisions contained in this Second Supplemental Indenture shall for any
reason be held to be invalid, illegal or unenforceable in any respect, such invalidity, illegality or unenforceability shall not affect any other provisions of this Second Supplemental Indenture, but
this Second Supplemental Indenture shall be construed as if such invalid or illegal or unenforceable provision had never been contained herein or therein. 


3







        IN WITNESS WHEREOF, the parties hereto have caused this Second Supplemental Indenture to be duly executed, and their respective seals to be hereunto affixed attested, all as of the day
and year first above written. 



	[Seal]	 	NORTHWESTERN ENERGY, L.L.C.
	

 	
 	

By:	

/s/  MICHAEL J. HANSON      
	 	 	 	
 Michael J. Hanson

President and Chief Executive Officer
	

ATTEST:	
 	

 	

 
	

 	
 	

 	

 
	/s/  ALAN D. DIETRICH      
 Alan D. Dietrich

Secretary	 	 	 
	

[Seal]	
 	

NORTHWESTERN CORPORATION
	

 	
 	

By:	

/s/  KIPP D. ORME      
	 	 	 	
 Kipp D. Orme

Vice President and Chief Financial Officer
	

ATTEST:	
 	

 	

 
	

 	
 	

 	

 
	/s/  ALAN D. DIETRICH      
 Alan D. Dietrich

Vice President—Legal Administration and Corporate Secretary	 	 	 
	

[Seal]	
 	

THE BANK OF NEW YORK, its Trustee
	

 	
 	

By:	

/s/  MARYBETH A. LEWICKI      
	 	 	 	
 MaryBeth A. Lewicki

Vice President
	

ATTEST:	
 	

 	

 
	

 	
 	

 	

 
	/s/        
 Name:

Title:	 	 	 









	STATE OF MONTANA	)
	 	) ss.:
	COUNTY OF SILVER BOW	)





        On
the 13th day of August, 2002, before me personally came David A. Monaghan, to me known, who, being by me duly sworn, did depose and say that she/he is Chief Financial Officer of
NorthWestern Energy, L.L.C., the limited liability company described in and which executed the foregoing instrument; and that she/he signed her/his name thereto. 


        IN
WITNESS WHEREOF, I have hereunto set my hand and affixed my seal of office this 13th day of August, 2002. 



	 	 
	 	/s/  KAREN L. SMOOK      
	 	










	STATE OF SOUTH DAKOTA	)
	 	) ss.:
	COUNTY OF MINNEHHA	)





        On
the 13th day of August, 2002, before me personally came Kipp D. Orme, to me known, who, being by me duly sworn, did depose and say that she/he is Vice President and Chief Financial
Officer of NorthWestern Corporation, one of the corporations described in and which executed the foregoing instrument; that she/he knows the seal of said corporation; that the seal affixed to said
instrument is such corporate seal; that it was so affixed by authority of the Board of Directors of said corporation; and that she/he signed her/his name thereto by like authority. 



        IN
WITNESS WHEREOF, I have hereunto set my hand and affixed my seal of office this 13th day of August, 2002. 



	 	 
	 	/s/  KAREN L. SMOOK      
	 	










	STATE OF NEW YORK	)
	 	) ss.:
	COUNTY OF NEW YORK	)





        On
the 13th day of August, 2002, before me personally came MaryBeth A. Lewicki, to me known, who, being by me duly sworn, did depose and say that she is a Vice President of The Bank of
New York, one of the corporations described in and which executed the foregoing instrument; that she knows the seal of said corporation; that the seal affixed to said instrument is such corporate
seal; that it was so affixed by authority of the Board of Directors of said corporation; and that she signed her name thereto by like authority. 



        IN
WITNESS WHEREOF, I have hereunto set my hand and affixed my seal of office this 13th day of August, 2002. 



	 	 
	 	/s/        
	 	












QuickLinks



EXHIBIT 4.2(z)