Exhibit 4.(b)(3)


 


FORM
OF SUPPLEMENTAL INDENTURE

(Senior Notes)



PUBLIC SERVICE COMPANY

OF COLORADO



TO



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

as Trustee



SUPPLEMENTAL INDENTURE



Dated as of                     





Supplementing the Indenture

dated as of July 1, 1999



Establishing the Securities of Series         

designated           % Senior
Notes due                           
















THIS                     
SUPPLEMENTAL INDENTURE, dated as of                         ,
is between PUBLIC SERVICE COMPANY OF COLORADO, a Colorado corporation
(hereinafter called the “Issuer” or the “Company”), having its principal office
at 1225 17th Street, Denver, Colorado 80202, and THE BANK OF NEW YORK TRUST
COMPANY, N.A., as Trustee (hereinafter called the “Trustee”), having its
principal corporate trust office at 101 Barclay Street, New York, New York
10286.


Recitals of the Issuer


The Issuer has heretofore executed and delivered an
Indenture, dated as of July 1, 1999 (the “Original Indenture”, the Original
Indenture, previously supplemented and as further supplemented by this
supplemental indenture being hereinafter referred to as the “Indenture”), relating
to the issuance at any time or from time to time of its Securities on terms to
be specified at the time of issuance. Terms used and not otherwise defined
herein shall (unless the context otherwise clearly requires) have the
respective meanings given to them in the Original Indenture.


The Original Indenture provides in Article Three
thereof that, prior to the issuance of Securities of any series, the form of
such Securities and the terms applicable to such series shall be established
in, or pursuant to, the authority granted in a resolution of the Board of
Directors or established in one or more indentures supplemental thereto.


The Issuer desires by this supplemental indenture,
among other things, to establish the form of the Securities of a series, to be
titled         % Notes due                                 
of the Issuer, and to establish the terms applicable to such series, pursuant
to Sections 201, 301 and 901 of the Original Indenture.  The Issuer has duly authorized the execution
and delivery of this supplemental indenture.


Article Nine of the Original Indenture provides that
the Issuer, when authorized by a resolution of its Board of Directors, and the
Trustee may from time to time and at any time amend the Indenture without the
consent of Securityholders for certain purposes enumerated in Section 901
thereof, including the purposes set forth in subsection (7) of said Section
901.


The execution and delivery of this supplemental
indenture by the parties hereto are in all respects authorized by the
provisions of the Indenture.


All things necessary have been done to make this
supplemental indenture a valid agreement of the Issuer, in accordance with its
terms.


NOW, THEREFORE, THIS             
SUPPLEMENTAL INDENTURE WITNESSETH:


For and in consideration of the premises, it is
mutually covenanted and agreed, as follows:













ARTICLE I



Establishment of % Notes due


Section 1.01.          The title of the series of the
Securities established by this supplemental indenture shall be         %
Notes due                                     
of the Issuer (hereinafter called the “Series       
Notes”).


Section 1.02.          The Series       
Notes shall be limited to [$                            ]
in aggregate principal amount.


Section 1.03.          The Series       
Notes may be issued in whole or in part as one or more Global Securities and
The Depository Trust Company, or a nominee thereof, shall be the Depository for
such Global Security or Global Securities. 
The Depository for such Global Security or Global Securities
representing Series        Notes may surrender
one or more Global Securities representing Series       
Notes in exchange in whole or in part for individual Series       
Notes on such terms as are acceptable to the Issuer and such Depository and
otherwise subject to the terms of the Indenture.


Section 1.04.          The principal of the Series       
Notes shall be payable on                                   .


Section 1.05.          The Series       
Notes shall bear interest at the rate of       %
per annum and shall accrue from                           .
The Interest Payment Dates shall be                         
and                           
in each year, commencing                               .
The Regular Record Dates in respect of such Interest Payment Dates shall be                                 
and                               
in each year, respectively.


Section 1.06.          The Corporate Trust Office of The Bank
of New York Trust Company, N.A. shall be the place at which the principal of
the Series        Notes shall be payable.  Any interest thereon shall be paid as
specified in Section 307 of the Original Indenture.


Section 1.07.          [Interest Payment Deferral Provisions,
if any.]


Section 1.08.          [Optional Redemption Provisions, if
any.]


Section 1.09.          [Mandatory Redemption Provisions, if
any.]


Section
1.10.                             The
Series        Notes shall be issued in
denominations of [$              ]
and any integral multiple thereof.


Section 1.11.          [Original Issue Discount Provisions,
if any.]


Section 1.12.          [Additional Defaults, if any.]


Section 1.13.          Sections 1301 and 1302 of the
Indenture shall be applicable to the Series       
Notes.



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Section 1.14.          [Currency, if other than U.S.
Dollars.]


Section 1.15.          [Additional Covenants, if any.]


Section 1.16.          The Issuer hereby appoints, or
confirms the appointment of, The Bank of New York Trust Company, N.A. as the
initial Trustee, Securities Registrar and Paying Agent, subject to the
provisions of the Indenture with respect to resignation, removal and
succession, and subject, further, to the right of the Issuer to appoint
additional agents (including Paying Agents).


Section 1.17.          [Exceptions to Business Day
Definition, if any.]


Section 1.18.          [Any Additional Terms.]


Section 1.19.          The Series       
Notes shall be substantially in the form set forth in Exhibit A hereto, and
shall have such further terms as are reflected in such form, subject to changes
in the form thereof made by the Issuer and acceptable to the Trustee.


ARTICLE II


Miscellaneous


Section 2.01.          The recitals contained herein shall be
taken as the statements of the Issuer, and the Trustee assumes no
responsibility for the correctness of the same. The Trustee makes no
representation as to the validity of this supplemental indenture. The
Indenture, as supplemented by this supplemental indenture, is in all respects
hereby adopted, ratified and confirmed.


Section 2.02.          This supplemental indenture may be
executed in any number of counterparts, and on separate counterparts, each of
which shall be an original; but such counterparts shall together constitute but
one and the same instrument.


Section 2.03.          If any provision of this supplemental
indenture limits, qualifies or conflicts with the duties imposed by any of
Sections 310 to 317, inclusive, of the Trust Indenture Act of 1939, as amended
by the Trust Indenture Reform Act of 1990, through operation of Section 318(c),
such imposed duties shall control.


Section 2.04.          The Article headings herein are for
convenience only and shall not affect the interpretation hereof.



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IN WITNESS WHEREOF, the parties hereto have caused
this Second Supplemental Indenture to be duly executed as of the         
day of                                   .


	
  

  	
  PUBLIC SERVICE COMPANY OF

  COLORADO 

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  By:

  	
   

  
	
   

  	
   

  	
  Name:

  	
   

  
	
   

  	
   

  	
  Title:

  	
   

  
	
   

  	
   

  
	
   

  	
   

  
	
   

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

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  By:

  	
   

  
	
   

  	
   

  	
  Authorized
  Signatory

  
							



 



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EXHIBIT A


Form of       % Note due                         


[THIS SECURITY IS A GLOBAL SECURITY REGISTERED IN THE
NAME OF THE DEPOSITORY (REFERRED TO HEREIN) OR A NOMINEE THEREOF AND UNLESS AND
UNTIL IT IS EXCHANGED IN WHOLE OR IN PART FOR THE INDIVIDUAL SECURITIES
REPRESENTED HEREBY, THIS GLOBAL SECURITY MAY NOT BE TRANSFERRED EXCEPT AS A
WHOLE BY THE DEPOSITARY TO A NOMINEE OF THE DEPOSITARY OR BY A NOMINEE OF THE
DEPOSITARY TO THE DEPOSITARY OR ANOTHER NOMINEE OF THE DEPOSITARY OR BY THE
DEPOSITARY OR ANY SUCH NOMINEE TO A SUCCESSOR DEPOSITARY OR A NOMINEE OF SUCH
SUCCESSOR DEPOSITARY.


UNLESS THIS CERTIFICATE
IS PRESENTED BY AN AUTHORIZED REPRESENTATIVE OF THE DEPOSITARY TRUST COMPANY, A
NEW YORK CORPORATION (55 WATER STREET, NEW YORK, NEW YORK), TO THE TRUSTEE FOR
REGISTRATION OF TRANSFER, EXCHANGE OR PAYMENT, AND ANY CERTIFICATE ISSUED IS
REGISTERED IN THE NAME OF CEDE & CO. OR IN SUCH OTHER NAME AS IS REQUESTED
BY AN AUTHORIZED REPRESENTATIVE OF THE DEPOSITARY TRUST COMPANY AND ANY PAYMENT
IS MADE TO CEDE & CO., 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.]


PUBLIC SERVICE COMPANY OF
COLORADO       % Note due                                         


	
  Interest Rate:

  	
   

  
	
   

  	
   

  
	
  Interest Payment
  Dates:

  	
   

  
	
   

  	
   

  
	
  Regular Record
  Dates:

  	
   

  
	
   

  	
   

  
	
  Original
  Interest Accrual Date:

  	
   

  
	
   

  	
   

  
	
  Stated Maturity:

  	
   

  
	
   

  	
   

  
	
  Registered No.

  	
  Principal Amount

  
	
   

  	
   

  
	
  CUSIP

  	
  $

  



 


PUBLIC SERVICE COMPANY OF COLORADO, a corporation duly
organized and existing under the laws of the State of Colorado (herein called
the “Company”, which term includes any successor corporation under the
Indenture referred to below) promises to pay to                               
or registered assigns the principal sum of                                               
Dollars on                                           
the Stated Maturity specified above.













1.                                       Interest.


The Company promises to pay interest on the principal
amount hereof at the Interest Rate per annum shown above from the Original
Interest Accrual Date specified above, or from the most recent Interest Payment
Date to which interest has been paid, semiannually in arrears, on the Interest
Payment Dates specified above, in each year, commencing with the Interest
Payment Date next succeeding the Original Interest Accrual Date specified
above, until the principal hereof is paid or duly provided for. Interest will
be computed on the basis of a 360-day year of twelve 30-day months.


2.                                       Method
of Payment.


The Company will pay interest so payable to the person
who is the registered holder hereof at the close of business on the Regular
Record Date for the next Interest Payment Date, except as otherwise provided in
the Indenture and except that interest payable at Maturity will be paid to the
person to whom principal is paid at Maturity. Payment of principal shall be
made upon presentation hereof at the office of this Paying Agent. The Company
will pay principal and interest in money of the United States that at the time
of payment is legal tender for payment of public and private debts. The Company
may pay principal and interest by check payable in such money. It may mail an
interest check to the holder’s registered address.


3.                                       Agents.


Initially, The Bank of New York Trust Company, N.A.,
101 Barclay Street, Floor 21 West, New York, New York 10286, Attention:
Corporate Trust Administration, will act as Paying Agent, and Securities
Registrar. The Company may change the Paying Agent to provide for more than one
such agent. The Company may appoint one or more Security Registers. The Company
or any Affiliate may act in any such capacity. The Trustee may appoint one or
more Authenticating Agents to authenticate the Securities.


4.                                       Indenture.


The securities of this series (the “Securities”) have
been issued under an Indenture dated as July 1, 1999 (the “Indenture”) between
the Company and The Bank of New York Trust Company, N.A. (the “Trustee,” which
term includes any successor trustee under the Indenture). The terms of the
Securities include those stated in the Indenture and in the Supplemental
Indenture creating the Securities and those made part of the Indenture by the
Trust Indenture Act of 1939 (15 U.S. Code Sections 77aaa-77bbbb). Securityholders
are referred to the Indenture, the Supplemental Indenture and the Act for a
statement of such terms.



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5.                                       Redemption.


[This Security is not redeemable prior to maturity.]
or [This Security is subject to redemption upon not less than 30 days’ notice
by first class mail, in whole or in part from time to time on and after             
at the option of the Company at a redemption price equal to                                 


In the event of redemption of this Security in part
only, a new Security or Securities of this series for the unredeemed portion
hereof will be issued in the name of the Holder hereof upon the cancellation
hereof.]


6.                                       [Notice
of Redemption.


Notice of redemption will be mailed at least 30 days
before the redemption date to the holder hereof at his address appearing on the
Security Register.


A notice of redemption shall provide that it is
subject to the occurrence of any event before the date fixed for such
redemption as described in such notice (“Conditional Redemption”) and such notice
of Conditional Redemption shall be of no effect unless all such conditions to
the redemption have occurred before such date or have been waived by the
Company.]


7.                                       Denominations,
Transfer, Exchange.


The Securities of this series are in registered form without
coupons in denominations of                         
and whole multiples of                     .
The transfer of this Security may be registered and this Security may be
exchanged as provided in the Indenture. The Securities Registrar may require a
holder, among other things, to furnish appropriate endorsements and transfer
documents and to pay any taxes and fees required by law or the Indenture. The
Securities Registrar need not exchange or register the transfer of any Security
of this series or portion thereof selected for redemption. Also, it need not
exchange or register the transfer of any Security for a period of 15 days
before a selection of Securities of this series to be redeemed.


8.                                       Persons
Deemed Owners.


The registered holder of a Security may be treated as
its owner for all purposes.


9.                                       Amendments
and Waivers.


Subject to certain exceptions, the Indenture may be
amended with the consent of the holders of a majority in outstanding principal
amount of the Securities. Subject to certain exceptions, a default under the
Indenture may be waived with the consent of the holders of a majority in
outstanding principal amount of the Securities.



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Without the consent of any Securityholder, the
Indenture may be amended, among other things, to cure any ambiguity, omission,
defect or inconsistency; to provide for assumption of Company obligations to
Securityholders; or to make any change that does not materially adversely
affect the rights of any Securityholder.


10.                                 Restrictive
Covenants.


The Securities are unsecured general obligations of
the Company limited to [$                          ]
principal amount. The Indenture does not limit the amount of debt the Company
may issue thereunder or otherwise.


11.                                 Successors.


When a successor assumes all the obligations of the
Company under the Securities and the Indenture, the Company will be released
from those obligations.


12.                                 Defeasance
Prior to Redemption or Maturity.


Subject to certain conditions, the Company at any time
may terminate some or all of its obligations hereunder and the Indenture if the
Company deposits with the Trustee money or U.S. Government Obligations for the
payment of principal and interest hereon to redemption or maturity. U.S.
Government Obligations are securities backed by the full faith and credit of
the United States of America or certificates representing an ownership interest
in such Obligations.


13.                                 Defaults
and Remedies.


If an Event of Default occurs and is continuing, the
Trustee or the holders of at least 25% in principal amount of the outstanding
Securities may declare the principal of all such Securities to be due and
payable immediately.  Securityholders may
not enforce the Indenture or the Securities except as provided in the
Indenture. The Trustee may require indemnity satisfactory to it before it
enforces the Indenture or the Securities. Subject to certain limitations,
holders of a majority in principal amount of the Securities may direct the
Trustee in its exercise of any trust or power. The Trustee may withhold from
Securityholders notice of any continuing default (except a default in payment
of principal or interest or any sinking fund installment) if it determines that
withholding notice is in their interests. The Company must furnish annual
compliance certificates to the Trustee.


14.                                 Trustee
Dealings with Company.


The Bank of New York Trust Company, N.A., the Trustee
under the Indenture, in its individual or any other capacity, may make loans
to, accept deposits from, and perform services for the Company or its
Affiliates, and may otherwise deal with the Company or its Affiliates, as if it
were not Trustee.



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15.                                 No
Recourse Against Others.


A director, officer, employee or stockholder, as such,
of the Company shall not have any liability for any obligations of the Company
under the Securities or the Indenture or for any claim based on, in respect of
or by reason of such obligations or their creation. Each Securityholder by
accepting a Security waives and releases all such liability. The waiver and
release are part of the consideration for the issue of the Securities.


16.                                 Authentication.


This Security shall not be valid for any purpose and
shall not be entitled to any benefit under the Indenture until authenticated by
a manual signature of the Trustee or any Authenticating Agent.


17.                                 Abbreviations.


Customary abbreviations may be used in the name of a
Securityholder or an assignee, such as: TEN COM (tenants in common), TEN ENT
(tenants by the entireties) , JT TEN (joint tenants with right of survivorship
and not as tenants in common), CUST (custodian), and U/G/M/A (Uniform Gifts to
Minors Act).


The Company will furnish to any Securityholder upon
written request and without charge a copy of the Indenture, including the
Supplemental Indenture which contains the text of this Security in larger type.
Requests may be made to: Public Service Company of Colorado, 1225 17th Street,
Denver, Colorado, 80202 attention: Corporate Secretary.



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  PUBLIC SERVICE COMPANY OF 

  COLORADO 

  
	
   

  	
   

  
	
   

  	
  By:

  	
   

  
	
   

  	
   

  	
  Name:

  	
   

  
	
   

  	
   

  	
  Title:

  	
   

  
	
   

  	
   

  
	
   

  	
   

  
	
     [corporate seal] 

  	
   

  
	
   

  	
   

  
	
  Attest:

  	
   

  	
   

  	
   

  
	
   

  	
  Name:

  	
   

  	
   

  	
   

  
	
   

  	
  Title:

  	
   

  	
   

  	
   

  
										



 


This is one of the Securities of the series designated
therein referred to in the within-mentioned Indenture.


	
  

  	
  THE BANK OF NEW YORK TRUST 

  COMPANY, N.A., as Trustee 

  
	
   

  	
   

  
	
   

  	
  By:

  	
   

  
	
   

  	
   

  	
  Authorized Signatory

  
	
   

  	
   

  
	
  Dated:

  	
   

  	
   

  	
   

  
					



 



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ASSIGNMENT FORM


To assign this Security, fill in the form below:


I or we assign and transfer this Security to:


	
  

  	
   

  	
   

  
	
   

  	
   

  	
   

  
	
  (Insert assignee’s social
  security or tax I.D. no.)

  
	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  



 


 


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


and irrevocably appoint                                         
agent to transfer this Security on the books of the Company. The agent may
substitute another to act for him.


	
  Date:

  	
  Your Signature:

  
	
   

  	
   

  
	
   

  	
   

  	
   

  	
   

  
				



 


(Sign exactly as your name appears on the other side
of this Security)



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