<PAGE>

                                                                    EXHIBIT 4.32


================================================================================


               This Supplemental Indenture is, among other things,
                             A MORTGAGE OF CHATTELS


                             SOUTHERN CALIFORNIA GAS
                                     COMPANY

                                       TO

                            BANKERS TRUST COMPANY OF
                                CALIFORNIA, N.A.
                                     TRUSTEE
                                  Successor to

                                WELLS FARGO BANK,
                              NATIONAL ASSOCIATION
                               Predecessor Trustee


                               -------------------


                             SUPPLEMENTAL INDENTURE
                   To Original Indenture dated October 1, 1940


                               -------------------


                          Dated as of January 15, 1988


================================================================================
<PAGE>

                                TABLE OF CONTENTS

                                                                            Page

PARTIES ..................................................................     1

RECITALS:

     Execution of Original Indenture and Supplements thereto .............     1
     Recording of Original Indenture and Supplements thereto .............     2
     Bonds heretofore issued .............................................     2
     Succession of Trustee to Predecessor Trustee ........................     3
     Creation of First Mortgage Bonds, Series U, due 1993 ................     3
     Lien on After Acquired Property .....................................     3
     Purpose of Supplemental Indenture ...................................     4
     Fulfillment of Conditions Precedent .................................     4
     Consideration and Authorization .....................................     4

SUCCESSION OF TRUSTEE AND GRANTING CLAUSES:

     Succession of Trustee ...............................................     4
     Real Property in California counties specified in Schedule A ........     5
     Plant, system and utilities in specified counties and elsewhere .....     5
     Other properties now or hereafter owned .............................     6
     Excepted properties .................................................     7

HABENDUM AND DECLARATION OF TRUST ........................................     7


                                   ARTICLE I.

                 AMOUNT, FORM, NUMBERING DENOMINATION, TRANSFER
                            AND EXCHANGE OF BONDS OF
                              SERIES U, DUE 1993.

SECTION 1.01.   Authorized amount of bonds of Series U, due 1993 .........     8

SECTION 1.02.   Bonds of Series U, due 1993; issuable as fully registered
                bonds; form of registered bonds and certificate ..........     8

SECTION 1.03.   Exchangeability of bonds .................................    12

SECTION 1.04.   Offices or agencies for payment, registration, transfer
                and exchange of bonds of Series U, due 1993 ..............    12

SECTION 1.05.   Certain conditions as to transfer, etc. of bonds of
                Series U, due 1993 .......................................    13
<PAGE>

                                       ii

                                                                            Page

                                   ARTICLE II.

                      INTEREST, MATURITY DATE, REDEMPTION,
                            RENEWAL FUND AND CERTAIN
                          OTHER PROVISIONS OF BONDS OF
                               SERIES U, DUE 1993.

SECTION 2.01.   Interest rate, maturity date and places and medium
                of payment ...............................................    13

SECTION 2.02.   Redemption of bonds of Series U, due 1993 ................    13

SECTION 2.03.   Renewal Fund for bonds of Series U, due 1993 .............    13

SECTION 2.04    Cancellation of bonds of Series U, due 1993 ..............    13

SECTION 2.05.   Other provisions of bonds of Series U, due 1993 ..........    13


                                  ARTICLE III.

                               SUNDRY PROVISIONS.

SECTION 3.01.   Trustee not responsible for recitals; recordation of
                Supplemental Indenture as required by law ................    14

SECTION 3.02.   Date of Supplemental Indenture and bonds of Series U,
                due 1993, are dates of identification ....................    14

SECTION 3.03.   Supplemental Indenture deemed to be part of Original
                Indenture ................................................    14

SECTION 3.04.   Trustee accepts trusts on same terms expressed in
                Original Indenture .......................................    14

SECTION 3.05.   Execution of Supplemental Indenture in counterparts ......    15

TESTIMONIUM ..............................................................    15

SIGNATURES AND SEALS .....................................................    16

ACKNOWLEDGMENTS .......................................................... 17-19

Schedule A ...............................................................    20
<PAGE>

               This Supplemental Indenture is, among other things,

                             A MORTGAGE OF CHATTELS

     THIS SUPPLEMENTAL INDENTURE, dated as of January 15, 1988, is made and
entered into in the city of Los Angeles, State of California by and between
SOUTHERN CALIFORNIA GAS COMPANY, a corporation duly organized and existing under
the laws of the State of California, and having its principal place of business
in the City of Los Angeles, State of California (hereinafter sometimes called
the "Corporation"), BANKERS TRUST COMPANY OF CALIFORNIA, N.A., a national
banking association duly organized and existing under the laws of the United
States of America and having its principal place of business in the City and
County of San Francisco, State of California (hereinafter, together with its
predecessors as trustees under the Indenture referred to below, sometimes called
the "Trustee"), and WELLS FARGO BANK, NATIONAL ASSOCIATION (formerly Crocker
National Bank), a national banking association duly organized and existing under
the laws of the United States of America and having its principal place of
business in the City and County of San Francisco, State of California
(hereinafter, together with its predecessors as trustees under the Indenture
referred to below, called the "Predecessor Trustee").


                                  WITNESSETH:

     WHEREAS, the Corporation has executed and delivered to the Predecessor
Trustee a certain Indenture (hereinafter sometimes called the "Original
Indenture") dated October 1, 1940, to secure bonds of the Corporation designated
generally as its "First Mortgage Bonds" to be issued from time to time in one or
more series, any of which series may vary from any other as to certain
particulars specified in Section 2.01 of the Original Indenture, and the
Corporation has executed and delivered to the Predecessor Trustee Supplemental
Indentures dated, respectively, as of July 1, 1947, May 1, 1948, June 1, 1950,
April 1, 1952, August 1, 1955, June 1, 1956, December 1, 1956, July 1, 1957,
October 1, 1959, July 1, 1963, September 1, 1964, and June 1, 1965, December 1,
1966, October 1, 1970, August 1, 1972, September 1, 1972, October 1, 1974, May
1, 1976, October 1, 1977, November 1, 1979, February 1, 1981, September 15,
1981, April 1, 1982, August 15, 1983, May 18, 1984, December 16, 1985, March 1,
1986, November 15, 1986 and December 1, 1986 supplementing and amending the
Original Indenture (the Original
<PAGE>

                                       2

Indenture together with this Supplemental Indenture and all other supplemental
indentures being herein collectively sometimes referred to as the "Indenture");
and

     WHEREAS, the Original Indenture and said Supplemental Indentures dated,
respectively, as of July 1, 1947, May 1, 1948, June 1, 1950, April 1, 1952 and
August 1, 1955,are recorded in the office of the County Recorder of each of the
Counties listed below in the Official Records thereof, as stated in said
Supplemental Indenture dated as of June 1, 1956; said Supplemental Indentures
dated, respectively, as of June 1, 1956 and December 1, 1956, are so recorded as
stated in said Supplemental Indenture dated as of July 1, 1957; said
Supplemental Indenture dated as of July 1, 1957 and each subsequently dated said
Supplemental Indenture (other than said Supplemental Indenture dated December 1,
1986) is so recorded as stated in said Supplemental Indenture dated as of the
next succeeding date; and said Supplemental Indenture dated as of December 1,
1986 is recorded in the offices of the County Recorders in the Counties of the
State of California, as follows:

    County                         Reference                          Date
    ------                         ---------                          ----

Fresno              Official Records, Document 86-138991        December 1, 1986
Imperial            Official Records, Document 86-18022         December 2, 1986
                    Book 1570, Pages 1226-1248
Kern                Official Records, Document 69454            December 1, 1986
                    Book 5943, Pages 540-562
Kings               Official Records, Document 17879            December 1, 1986
                    Book 1391, Pages 363-385
Los Angeles         Official Records, Document 86-1662637       December 2, 1986
Orange              Official Records, Document 86-587999        December 1, 1986
Riverside           Official Records, Document 304286           December 1, 1986
San Bernardino      Official Records, Document 86-361727        December 1, 1986
San Diego           Official Records, Document 86-554954        December 2, 1986
San Luis Obispo     Official Records, Document 79290            December 1, 1986
                    Vol. 2919, Pages 194-216
Santa Barbara       Official Records, Document 1986-077832      December 1, 1986
Tulare              Official Records, Document 68543            December 1, 1986
                    Vol. 4502, Pages 370-392
Ventura             Official Records, Document 86-173706        December 1, 1986

     WHEREAS, bonds of the Corporation of thirteen (13) series designated,
respectively, as its "First Mortgage Bonds, Series E, due 1988", "First Mortgage
Bonds, Series F, due 1989", "First Mortgage Bonds, Series G, due
<PAGE>

                                       3

1991", "First Mortgage Bonds, Series H, due 1995", "First Mortgage Bonds, Series
I, Due 1997", "First Mortgage Bonds, Series K, due 1996", "First Mortgage Bonds,
Series L, due 1997", "First Mortgage Bonds, Series M, due 1999", "First Mortgage
Bonds, Series N, due 2001", "First Mortgage Bonds, Series Q, due 1993", "First
Mortgage Bonds, Series R, due 2016", "First Mortgage Bonds, Series S, due 1996"
and "First Mortgage Bonds, Series T, due 2016" are outstanding as a part of the
First Mortgage Bonds referred to in the Original Indenture, each series of
bonds, unless and until the taking of further appropriate action by the Board of
Directors of the Corporation, being without limitation as to aggregate
authorized principal amount; and

     WHEREAS, the Trustee has succeeded to the estates, properties, rights,
powers, trusts, duties and obligations of the Predecessor Trustee under the
Original Indenture, as heretofore supplemented and amended, but the Corporation,
the Trustee and the Predecessor Trustee, nevertheless, desire to execute,
acknowledge, deliver and cause to be recorded this Supplemental Indenture for
the purposes, among others, of evidencing such succession; and

     WHEREAS, pursuant to the provisions of Sections 2.01 and 2.02 of the
Original Indenture, the Board of Directors of the Corporation has, by resolution
duly adopted and delivered to the Trustee, created, as a part of the first
Mortgage Bonds referred to in the Original Indenture, a new series of bonds
designated "First Mortgage Bonds, Series U, due 1993" (herein sometimes called
"bonds of Series U"), to be of the form, terms and provisions provided in that
resolution and herein, which new series of bonds, unless and until the taking of
further appropriate action by the Board of Directors of the Corporation, is to
be without limitation as to aggregate authorized principal among and of which
series bonds in the aggregate principal amount of $100, 000,000 are to be
presently issued; and

     WHEREAS, it is provided in the Original Indenture that all the business,
franchises and properties, real, personal, and mixed, of every kind and nature
whatsoever and wheresoever situate, which might thereafter be acquired by the
Corporation, shall be as fully embraced within the lien thereof as if said
properties were owned by the Corporation at the date of the Original Indenture
and were particularly described therein and specifically conveyed thereby,
excepting certain properties expressly excepted by the provisions thereof; and

     WHEREAS, subsequent to the execution of the Original Indenture the
Corporation has acquired properties hereinafter mentioned or referred to, all
<PAGE>

                                       4

of which properties, upon the acquisition thereof by the Corporation, became and
now are subject to the lien, operation and effect of the Original Indenture by
virtue of the after-acquired property clause or other clauses thereof; but the
Corporation, nevertheless, desires to execute, acknowledge, deliver and cause to
be recorded this Supplemental Indenture for the purposes, among others, of
expressly and specifically subjecting such after-acquired properties to the lien
of the Original Indenture as supplemented and of further assuring and confirming
the lien of the Original Indenture as supplemented on all of the properties of
every kind and character, whether real or personal and regardless of the date of
acquisition thereof by the Corporation, intended to be subjected to the lien
thereof; and

     WHEREAS, under the provisions of Sections 2.02 and 16.01 of the Original
Indenture the Corporation and the Trustee are authorized to execute and deliver
an indenture supplemental to the Original Indenture (i) to set forth the
particulars, permitted by Section 2.01 of the Original Indenture, as to which
the bonds of Series U are to vary from the bonds of the other series of said
First Mortgage Bonds, and (ii) for any purpose not inconsistent with the terms
of the Indenture; and

     WHEREAS, for and in consideration of the premises the Corporation desires
to execute this Supplemental Indenture; and

     WHEREAS, the making, executing, delivering and recording of this
Supplemental Indenture have been duly authorized by proper corporate action of
the Corporation; and

     WHEREAS, the execution and delivery of this Supplemental Indenture have
been authorized by the Public Utilities Commission of the State of California:

     NOW THEREFORE, in consideration of the premises and of the sum of one
dollar ($1), lawful money of the United States of America, duly paid by the
Trustee to the Corporation and to the Predecessor Trustee, and of other good and
valuable consideration, receipt of which is hereby acknowledged, and (a) in
order to evidence the succession of the Trustee to the Predecessor Trustee as
trustee under the Original Indenture, as heretofore supplemented and amended,
the Trustee and the Predecessor Trustee hereby confirm that the Trustee has
succeeded to the estates, properties, rights, powers, trusts, duties and
obligations of the Trustee under the Original Indenture, as heretofore
supplemented and amended, by virtue of operation of law pursuant to the
provisions of Section 2050 et. seq. of the California
<PAGE>

                                       5

Financial Code and Article XIV of the Original Indenture and the Trustee
confirms that it is eligible under the provisions of Sections 5.13 and 14.01 and
qualified under Section 14.14 of the Original Indenture; and, (b) in order (i)
to set forth or specify (A) the form of the fully registered bonds of Series U,
and the form of the certificate to be endorsed on all bonds of said series, and
(B) the terms and provisions of the bonds of Series U, including the particulars
thereof which vary from the bonds of the other series of said First Mortgage
Bonds, and (ii) to further secure the payment of both the principal of and
interest on the bonds of the Corporation now or at any time hereafter
outstanding under the Original Indenture and/or any indenture supplemental
thereto, including specifically, but without limitation, all of said First
Mortgage Bonds now outstanding and said $100,000,000 aggregate principal amount
of bonds of Series U, according to their tenor and effect, and further to secure
the observance and performance of all of the covenants, agreements and
conditions contained in the Original Indenture or in any indenture supplemental
thereto, and without in any way limiting the generality or effect of the
Indenture insofar as by any provision thereof any of the property therein or
hereafter described or referred to is now subject or intended to be subject to
the lien and operation thereof, but to such extent confirming such lien and
operation, the Corporation has executed and delivered this Supplemental
Indenture and has granted, bargained, sold, released, conveyed, mortgaged,
assigned, transferred, pledged, set over and confirmed, and does hereby grant,
bargain, sell, release, convey, mortgage, assign, transfer, pledge, set over and
confirm unto Bankers Trust Company of California, N.A., the Trustee, and to its
successor or successors in the trust created by the Original Indenture and/or
any indenture supplemental thereto, and to its and their assigns, forever, with
power of sale, subject, to the extent applicable by the terms of the Indenture
to any of the properties hereinafter referred to or described, to the exceptions
(other than as expressly provided in the granting clauses of said Supplemental
Indentures dated respectively as of June 1, 1956, July 1, 1957, October 1, 1959,
July 1, 1963, September 1, 1964 and December 1, 1966 with respect to exception
(f) set forth on page 67 of the Original Indenture and reading as follows: "(f)
Any gas and/ or oil acreage, gas and/or oil wells, gas and/or oil reserves, or
gas and/or oil leaseholds hereafter acquired by the Corporation, or any property
or equipment now or hereafter owned by the Corporation and used for the
development of gas and/or oil acreage or for the drilling for or production of
gas and/or oil from such acreage"; which exception (f) is by said granting
clauses
<PAGE>

                                       6

expressly made inapplicable to certain therein specified parcels of property),
reservations, conditions, terms and provisions provided in the Indenture with
respect to properties subject or intended to be subject thereto, all of the
properties and assets of the corporation, real, personal and mixed, of every
kind and character, whether now or hereafter owned by the Corporation and
wheresoever situated, including, without in any way limiting or modifying the
generality or effect of the foregoing, all and singular, the following
properties:

     FIRST: All of the lots, pieces and parcels of land and rights or interests
in real property situate in the Counties in the State of California,
specifically described and mentioned or enumerated in Schedule A attached
hereto, to which reference is hereby made and the same is made a part hereof
with the same force and effect as if the same were here set forth at length.

     SECOND: All and singular the plants, properties, equipment, real and
personal property, estates, interests, goodwill, generating, transmission,
feeding, storing, and distribution systems, and utilities of the Corporation
situate in the Counties of Fresno, Imperial, Kern, Kings, Los Angeles, Orange,
Riverside, San Bernardino, San Diego, San Luis Obispo, Santa Barbara, Tulare and
Ventura, and elsewhere, in the State of California, with all and singular the
franchises, ordinances, grants, easements, licenses, powers, immunities,
permits, privileges, appurtenances, tenements and other rights and property
thereunto appertaining or belonging, as the same now exist and as the same and
any and all parts thereof may hereafter exist or be improved, added to,
enlarged, extended or acquired in said counties or elsewhere in said state or
any other state or states.

     THIRD: All other property, real, personal and mixed, of every kind, nature
and description (including, without in any way limiting the effect or the
generality hereof, all facilities: all stocks, bonds and other securities from
time to time conveyed, assigned, transferred, mortgaged or pledged on behalf of
the Corporation, or with its consent, to the Trustee in the manner and for the
purposes as provided in the Indenture; all gas manufacturing plants, boilers,
engines, compressors, motors, pumps, generators, gasholders, tanks, appliances,
oil storage facilities, gas storage facilities, wells, buildings, structures,
plants, works and other improvements; all gas transmission and distributing
lines and systems: all meters and regulators and all other apparatus, machinery,
appliances, tools, furniture, fixtures, supplies, facilities and utilities and
other personal property; or any right or interest in any thereof; all business
and goodwill, rights, consents, franchises, ordinances, licenses,
<PAGE>

                                       7

agreements, contracts, permits, easements, rights of way, leases and leasehold
interests; powers, grants, privileges and immunities to construct, operate and
maintain lines and other facilities or properties for conveying gas or other
commodity or utility for any purpose or purposes through, under and over public
streets or highways, or public or private places or property; all reversions,
remainders, tolls, incomes, revenues, earnings, rents, issues and profits of any
property, real, personal and mixed; and all other classes and types of property
described or referred to in the Original Indenture, or any indenture
supplemental thereto), now or hereafter owned, held, possessed, acquired or
enjoyed by or in any manner conferred upon or appertaining to the Corporation,
including the interest of the Corporation in all leases now or hereafter owned
by it, together with all and singular the tenements, hereditaments, and
appurtenances belonging or in any way appertaining to each and every part of any
and all property subject or intended to be subject to the lien and operation of
the Original Indenture as supplemented, and the reversion and reversions,
remainder and remainders, tolls, incomes, revenues, earnings, rents, issues and
profits thereof.

     SAVING AND EXCEPTING, however, from the property hereby mortgaged, conveyed
in trust and/or pledged, all property, whether now owned by the Corporation or
hereafter acquired by it, expressly saved and excepted from the lien of the
Indenture and therein referred to as the "excepted property" (except as
otherwise expressly provided in any Supplemental Indenture hereinabove
mentioned, with respect to exception (f) of said "excepted property"), unless
and until, upon the occurrence of an event of default under the Indenture, the
Trustee, or any receiver appointed thereunder, shall take possession of any or
all of such excepted property.

     TO HAVE AND TO HOLD in trust with power of sale for the equal and
proportionate benefit and security of all holders of bonds of the Corporation,
now or hereafter outstanding under the Indenture as from time to time in effect,
and for the enforcement and payment of said bonds and interest thereon when
payable, and the performance of and compliance with the covenants and conditions
of the Indenture as from time to time in effect, without any preference,
distinction or priority as to lien or otherwise of any of said bonds over any
others thereof by reason of the difference in the time of the actual issue, sale
or negotiation thereof, or for any other reason whatsoever, except as otherwise
expressly provided in the Indenture as from time to time in effect, so that each
and every such bond shall have the same lien and so that the principal and
interest of every such bond shall, subject to the
<PAGE>

                                       8

terms thereof, be equally and proportionately secured by said lien, as if such
bond had been made, executed, delivered, sold and negotiated simultaneously with
the execution and delivery of the Original Indenture.

     IT IS HEREBY COVENANTED, DECLARED, AND AGREED by and between the parties
hereto that all such bonds are issued, authenticated and delivered, or are to be
issued, authenticated and delivered, and that all property subject, or to become
subject, to the Original Indenture, including any indenture supplemental
thereto, is to be held, subject to the covenants, conditions, uses and trusts
therein set forth.

     It is hereby further stipulated and provided:


                                    ARTICLE I

                     AMOUNT, FORM, NUMBERING, DENOMINATION,
                         TRANSFER AND EXCHANGE OF BONDS
                              OF SERIES U, DUE 1993

     Section 1.01. The bonds of Series U may be issued at any time or from time
to time upon and subject to the terms and provisions of the Indenture. Unless
and until the taking of further appropriate action by the Board of Directors of
the Corporation the bonds of said Series shall be without limitation as to
aggregate authorized principal amount.

     Section 1.02. The bonds of Series U shall be issued only as fully
registered bonds without coupons. The fully registered bonds without coupons and
the certificate of authentication to be endorsed on all bonds of said Series
shall be substantially in the following form:



          [FORM OF REGISTERED BOND WITHOUT COUPONS, SERIES U, DUE 1993]

                         SOUTHERN CALIFORNIA GAS COMPANY
            [Incorporated under the laws of the State of California]
                     FIRST MORTGAGE BOND, SERIES U, DUE 1993
                                    (8 7/8%)

No. ________                                                       $____________

     SOUTHERN CALIFORNIA GAS COMPANY, a corporation organized and existing under
the laws of the State of California (hereinafter
<PAGE>

                                       9

called the "Corporation", which term shall include any successor corporation, as
defined the Indenture hereinafter referred to), for value received, hereby
promises to pay to _____________________________________________________________
or registered assigns, the principal sum of ___________________ DOLLARS in
lawful money of the United States of America, on the fifteenth day of January,
1993, and to pay interest thereon to the registered owner hereof from the date
of this bond, at the rate of 8 7/8% per annum in like lawful money, payable
semi-annually, on the fifteenth days of January and July in each year,
commencing July 15, 1988 until the Corporation's obligation with respect to the
payment of such principal shall be discharged as provided in the Indenture
hereinafter mentioned. Both the principal of and interest on this bond will be
paid at the corporate trust office of Bankers Trust Company of California, N.A.,
or its successor trustee under said Indenture, in the City and County of San
Francisco, State of California or at the corporate trust office of the Trustee
in the City of Los Angeles, State of California, or, at the option of the
registered owner hereof, principal will be paid at the office or agency of the
Corporation in the City of New York, State of New York.

     The provisions of this bond are continued on the reverse hereof and such
continued provisions shall for all purposes have the same effect as though set
forth at this place.

     IN WITNESS WHEREOF, SOUTHERN CALIFORNIA GAS COMPANY has caused this bond to
be signed in its corporate name by the facsimile signature of its authorized
officer and a facsimile of its corporate seal to be hereto affixed and attested
by its Secretary or an Assistant Secretary.

     Dated:

                                       SOUTHERN CALIFORNIA GAS COMPANY


                                       By
                                          -----------------------------
                                          Vice President and Controller

(CORPORATE SEAL)

Attest:


-----------------------------------
             Secretary
<PAGE>

                                       10

                    [REVERSE SIDE -- FORM OF REGISTERED BOND
                      WITHOUT COUPONS, SERIES U, DUE 1993]

     This bond is one of a duly authorized issue of bonds of the Corporation
(herein called the "bonds"), of the series hereinafter specified, all issued and
to be issued under and all equally and ratably secured by a mortgage and deed of
trust dated October 1, 1940, between the Corporation and Bankers Trust Company
of California, N.A., as successor trustee, to which mortgage and deed of trust
and all indentures supplemental thereto, including Supplemental Indentures
dated, respectively, as of July 1, 1947, August 1, 1955, June 1, 1956, December
1, 1956, June 1, 1965, August 1, 1972, May 1, 1976, September 15, 1981, and May
18, 1984 (herein collectively referred to as the "Indenture"), reference is
hereby made for a description of the property conveyed in trust, mortgaged and
pledged, the nature and extent of the security, the rights of the registered
owners of the bonds and of the Trustee or trustees in respect thereof, the terms
and conditions upon which the bonds are, and are to be, secured and the
circumstances under which additional bonds may be issued. The bonds may be
issued for various principal sums and may be issued in series, which may mature
at different times, may bear interest at different times, may bear interest at
different rates and may otherwise vary as in the Indenture provided. This bond
is one of a series designated as the "First Mortgage Bonds, Series U, due 1993"
(herein called "bonds of Series U") of the Corporation, issued under and secured
by the Indenture.

     As provided in the Indenture, by any indenture or indentures supplemental
thereto executed by the Corporation and the Trustee and consented to by the
holders of not less than two-thirds (2/3) in principal amount of the bonds at
the time outstanding, and, in case one or more, but less than all, of the series
of bonds then outstanding are affected by such supplemental indenture, consented
to by the holders of at least two-thirds (2/3) in principal amount of the bonds
of each series so affected, the Indenture or any indenture supplemental thereto
and the rights and obligations of the Corporation and the holders of bonds, may
be modified or altered from time to time, as provided in the Indenture;
provided, however, (a) that the right of any holder of any bond to receive
payment of the principal of the interest on such bond, on or after the
respective due dates expressed in such bond, or to institute suit for the
enforcement of any such payment on or after such respective dates, shall not be
impaired or affected by any such supplemental indenture without the consent of
such holder, and (b) that no such modification or alteration shall
<PAGE>

                                       11

reduce the proportions of bondholders' consents required as aforesaid; such
proportions to be determined in each case as provided in the Indenture.

     The bonds of Series U are entitled to the benefits of the Renewal Fund as
provided in the Indenture.

     The bonds of Series U are not subject to redemption prior to maturity.

     In case an event of default, as defined in the Indenture, shall occur, the
principal of all bonds then outstanding under the Indenture may be declared or
become due and payable upon the conditions and in the manner and with the effect
provided in the Indenture.

     This bond is transferable by the registered owner hereof at the office or
agency of the Corporation in said City and County of San Francisco, in said City
of Los Angeles, in the borough of Manhattan, City of New York and in such other
place or places as the Corporation may designate at any time or from time to
time, and thereupon a new fully registered bond or bonds of said series, without
coupons, of authorized denomination or denominations, of a like aggregate
principal amount, will be issued to the transferee or transferees in exchange
for this bond; and at any of said offices or agencies fully registered bonds of
Series U, without coupons, are exchangeable for a like aggregate principal
amount of other such fully registered bonds of authorized denominations; all in
the manner and subject to the conditions as provided in the Indenture.

     No recourse shall be had for the payment of the principal of or the
interest on this bond or for any claim based hereon or on the Indenture or any
indenture supplemental thereto, against any incorporator, stockholder, director
or officer, past, present or future, of the Corporation, or of any predecessor
or successor corporation, either directly or through the Corporation, or any
such predecessor or successor corporation, whether by virtue of any
constitution, statute or rule of law, or by the enforcement of any assessment or
penalty, or otherwise, all such liability being waived and released by every
registered owner hereof by the acceptance of this bond and as part of the
consideration for the issue hereof, and being likewise waived and released by
the terms of the Indenture.

     This bond shall not become valid or obligatory for any purpose or be
entitled to any benefit under the Indenture until Bankers Trust Company of
California, N.A., or its successor as Trustee under the Indenture, or an
<PAGE>

                                       12

authenticating agent, shall have signed the form of certificate endorsed hereon.



                     [FORM OF CERTIFICATE OF AUTHENTICATION]

                                   CERTIFICATE

     This bond is one of the bonds, of the series designated therein, described
in the within-mentioned Indenture.

      BANKERS TRUST COMPANY,          or          BANKERS TRUST COMPANY,
       OF CALIFORNIA, N.A.,                        Authenticating Agent
             Trustee

By                                          By
   ------------------------------              ------------------------------
         Authorized Officer                          Authorized Officer

     The bonds of Series U may contain or have imprinted thereon such provisions
or specifications not inconsistent with the Indenture as may be required to
comply with the rules of any stock exchange or any federal or state authority or
commission, or to comply with usage with respect thereto, and may bear such
other appropriate endorsements or notations as are authorized or permitted by
the Indenture.

     The fully registered bonds of Series U shall be assumable in denominations
of $1,000 and any multiple of $1,000 and shall be dated as provided in paragraph
1 of Section 2.01 of the Original Indenture. The definitive bonds of Series U
shall be numbered in such manner as the Corporation shall at any time or from
time to time determine.

     SECTION 1.03. In the manner and subject to certain conditions and
limitations specified herein and in the Indenture, bonds of Series U may be
exchanged without a service charge for a like aggregate principal amount of such
bonds of Series U of other authorized denomination or denominations.

     SECTION 1.04. The Corporation shall maintain in the City and County of San
Francisco and in the City of Los Angeles, State of California, and also in the
Borough of Manhattan, City of New York, State of New York, and in such other
place or places as the Corporation may designate at any time or from time to
time, an office or agency where bonds of Series U may be presented for payment,
registration, transfer and exchange as provided therein or in the Indenture.
Such office or agency in the City and County of San
<PAGE>

                                       13

Francisco shall be the corporate trust office of the Trustee, such office or
agency in the city of Los Angeles shall be the corporate trust office of the
Trustee in said City, and such office or agency in the Borough of Manhattan,
City of New York shall be the principal office of Bankers Trust Company unless
and until the Corporation shall designate another office or agency by notice in
writing delivered to the Trustee.

     SECTION 1.05. No transfer or exchange of any bonds of Series U pursuant to
any of the provisions of this Article I shall be made except upon and in
accordance with all of the applicable terms, provisions and conditions of said
bond and of the Indenture.


                                   ARTICLE II

              INTEREST, MATURITY DATE, REDEMPTION, RENEWAL FUND AND
                 CERTAIN OTHER PROVISIONS OF BONDS OF SERIES U,
                                    DUE 1993.

     SECTION 2.01. The bonds of Series U shall bear interest at the rate, shall
be expressed to mature as to principal, and shall be payable as to principal and
interest at such place or places and in such money, all as provided in the form
of such bonds set forth in Section 1.02 hereof and by the applicable provisions
of the Indenture.

     SECTION 2.02. The bonds of Series U shall not be subject to redemption
prior to maturity.

     SECTION 2.03 The bonds of Series U shall be entitled to the benefits of the
Renewal Fund as provided in the Indenture.

     SECTION 2.04. The Corporation may at any time deliver to the Trustee for
cancellation any bonds of Series U previously authenticated and delivered under
the Indenture which the Corporation may have acquired in any manner whatsoever
and all bonds of Series U so delivered shall be promptly cancelled by the
Trustee upon the request of the Corporation.

     SECTION 2.05 The bonds of Series U shall, except as in this Supplemental
Indenture otherwise expressly provided, be on the terms and provisions, and
shall represent such rights and be entitled to such benefits, as are applicable
thereto by the terms of the Indenture.
<PAGE>

                                       14

                                   ARTICLE III

                               SUNDRY PROVISIONS.

     SECTION 3.01. The recitals of fact contained herein shall be taken as the
statements of the Corporation, and the Trustee assumes no responsibility for the
correctness of the same. The Corporation hereby covenants and agrees that it
will cause this Supplemental Indenture to be kept recorded and/or filed as may
be required by law, in such manner and in such places as may be necessary fully
to preserve and protect the security of the bondholders and all of the rights of
the Trustee hereunder, and that it will with all reasonable dispatch deposit
with the Trustee counterparts of this Supplemental Indenture bearing official
notation or endorsements showing such recordation and/or filing, or in case such
counterparts are not returned to the Corporation, furnish to the Trustee the
best official evidence of such recordation and/or filing reasonably obtainable
by the Corporation, or evidence of the taking of such other action, if any, but
the Trustee, subject to the provisions of Sections 14.02 and 14.03 of said
Original Indenture, shall in no wise be liable for any failure or omission in
this regard.

     SECTION 3.02. The date of this Supplemental Indenture and the date of the
bonds of Series U are intended as and for a date for the convenient
identification of this Supplemental Indenture and of the bonds of said series,
and are not intended to indicate that this Supplemental Indenture was executed
and delivered or that said bonds were executed, delivered or issued on said
date; it being hereby provided that this Supplemental Indenture may be executed
and delivered, and that said bonds may be executed, delivered or issued, either
on said date or before or after said date, and that this Supplemental Indenture
is in fact executed and delivered by each party hereto on the date of its
certificate of acknowledgement hereto attached.

     SECTION 3.03. This Supplemental Indenture shall be deemed to be part of the
Original Indenture, and the Corporation agrees to conform to and comply with all
and singular the terms, provisions, conditions and covenants set forth therein
and herein. This Supplemental Indenture shall be construed in connection with
and as a part of the Original Indenture, as heretofore amended and supplemented.

     SECTION 3.04. It is further agreed that the Trustee accepts the trust
imposed upon it by this Supplemental Indenture, upon and subject to the
<PAGE>

                                       15

same terms and conditions as are expressed in Article XIV of the Original
Indenture.

     SECTION 3.05. In order to facilitate the recording of this Supplemental
Indenture, the same may be executed in several counterparts, each of which so
executed shall be deemed to be an original, and such counterparts shall
collectively constitute one and the same instrument.

     IN WITNESS WHEREOF, Southern California Gas Company has caused this
Supplemental Indenture to be signed in its corporate name by one of its Vice
Presidents or its Treasurer and its Secretary or an Assistant Secretary and its
corporate seal to be hereunto duly affixed, Bankers Trust Company of California,
N.A., in token of its succession to the trust established by the Original
Indenture and acceptance of the trust hereby established, has caused this
Supplemental Indenture to be signed in its corporate name by one of its Vice
Presidents and its Secretary or an Assistant Secretary, and its corporate seal
to be hereunto duly affixed, and Wells Fargo Bank, National Association, in
token of the succession to it by Bankers Trust Company of California, N.A., of
the trust established by the Original Indenture, has caused this Supplemental
Indenture to be signed in its corporate
<PAGE>

                                       16

name by one of its Vice Presidents and one of its Assistant Secretaries, and its
corporate seal to be hereunto duly affixed, all as of January 15, 1988.


Attest:                                SOUTHERN CALIFORNIA GAS COMPANY



     VIRGINIA A. ROBINSON              By         H.T. JOHNSON
------------------------------            ------------------------------
          Secretary                                 Treasurer


(SEAL)


ATTEST:                                BANKERS TRUST COMPANY OF
                                       CALIFORNIA, N.A.


           L. LOPES                    By          J.M. KELDSEN
------------------------------            ------------------------------
      Assistant Secretary                         Vice President


(SEAL)


ATTEST:                                WELLS FARGO BANK, NATIONAL
                                       ASSOCIATION

        JACK W. WETZEL                 By          DOROTHY HAIR
------------------------------            ------------------------------
      Assistant Secretary                         Vice President


(SEAL)
<PAGE>

                                       17

STATE OF CALIFORNIA     ) ss.:
COUNTY OF LOS ANGELES   )

     On this 15th day of January, 1988, before me, Christina E. Tracy, a Notary
Public of the State of California, duly commissioned and sworn, personally
appeared H. T. Johnson, personally known to me (or proved to me on the basis of
satisfactory evidence) to be the Treasurer, and Virginia A. Robinson, personally
known to me (or proved to me on the basis of satisfactory evidence) to be the
Secretary, of SOUTHERN CALIFORNIA GAS COMPANY, one of the corporations named in
and which executed the foregoing instrument, personally known to me (or proved
to me on the basis of satisfactory evidence) to be the persons who executed the
within instrument on behalf of said Corporation, and acknowledged to me that
said Corporation executed the same, and acknowledged to me that said Corporation
executed the within instrument pursuant to its by-laws or a resolution of its
Board of Directors.

     IN WITNESS WHEREOF, I have hereunto set my hand and affixed my official
seal the day and year in this certificate first above written.



                                             CHRISTINA E. TRACY
                                       ------------------------------
                                            Notary Public of the
                                            State of California

                                                                          (SEAL)


My Commission Expires August 29, 1989.
<PAGE>

                                       18

STATE OF CALIFORNIA     ) ss.:
COUNTY OF SAN FRANCISCO )

     On this 15th day of January, 1988, before me, Daniel J. Nerney, a Notary
Public of the State of California, duly commissioned and sworn, personally
appeared M. Keldsen, personally known to me (or proved to me on the basis of
satisfactory evidence) to be a Vice President, and L. Lopes, personally known to
me (or proved to me on the basis of satisfactory evidence) to be an Assistant
Secretary, of BANKERS TRUST COMPANY OF CALIFORNIA, N.A., one of the corporations
named in and which executed the foregoing instrument, personally known to me (or
proved to me on the basis of satisfactory evidence) to be the persons who
executed the within instrument on behalf of said Corporation, and acknowledged
to me that said Corporation executed the within instrument pursuant to its
by-laws or a resolution of its Board of Directors.

     IN WITNESS WHEREOF, I have hereunto set my hand and affixed my official
seal the day and year in this certificate first above written.



                                              DANIEL J. NERNEY
                                       ------------------------------
                                            Notary Public of the
                                            State of California

                                                                          (SEAL)


My Commission expires May 20, 1991.
<PAGE>

                                       19

STATE OF CALIFORNIA     ) ss.:
COUNTY OF SAN FRANCISCO )

     On this 15th day of January, 1988, before me, Daniel J. Nerney, a Notary
Public of the State of California, duly commissioned and sworn, personally
appeared Dorothy Hair, personally known to me (or proved to me on the basis of
satisfactory evidence) to be a Vice President, and Jack W. Wetzel, personally
known to me (or proved to me on the basis of satisfactory evidence) to be an
Assistant Secretary, of WELLS FARGO BANK, NATIONAL ASSOCIATION, one of the
corporations named in and which executed the foregoing instrument, personally
known to me (or proved to me on the basis of satisfactory evidence) to be the
persons who executed the within instrument on behalf of said Corporation, and
acknowledged to me that said Corporation executed the within instrument pursuant
to its by-laws or a resolution of its Board of Directors.

     IN WITNESS WHEREOF, I have hereunto set my hand and affixed my official
seal the day and year in this certificate first above written.



                                              DANIEL J. NERNEY
                                       ------------------------------
                                            Notary Public of the
                                            State of California

                                                                          (SEAL)


My Commission expires May 20, 1991.
<PAGE>

                                       20

                                   SCHEDULE A

     Incorporated in and made a part of the Supplemental Indenture dated as of
January 15, 1988, among Southern California Gas Company, Bankers Trust Company
of California, N.A., Trustee, and Wells Fargo Bank, National Association,
Predecessor Trustee.

     The descriptive names or captions do not constitute a part of the property
descriptions, being used only for convenience of reference and identification.


                              COUNTY OF LOS ANGELES

     Those certain lots, pieces and parcels of land and other property, rights,
and estates situate in the County of Los Angeles, State of California, described
as follows:


                            Saticoy Distribution Base

     Those portions of Lot 603 of Tract No. 1000, in the City of Los Angeles,
County of Los Angeles, State of California, as per map recorded in Book 19,
pages 1 through 34, inclusive, of Maps, in the office of the County Recorder of
said County, described as follows:

     Beginning at the intersection of the easterly line of said Lot 603 with the
northerly line of the southerly 17.00 feet of said Lot; thence along said
easterly line North 0(0)01'27" West 856.43 feet to the southerly line of the
northerly 422.50 feet of said Lot; thence along said southerly line North
89(0)59'44" West 138.91 feet to the easterly line the 80.00 foot strip of land
for flood control, described as Parcel 51, as condemned by Final Decree of
Condemnation entered in Case No. 560084 of the Superior Court, in the State of
California, in and for the County of Los Angeles, a certified copy thereof being
recorded in Book 38503, page 115 of Official Records, in the office of said
County Recorder; thence along said last mentioned easterly line and along the
easterly line of the land described as Parcel 50 in certified copy of said Final
Decree recorded in Book 42894, page 361 of said Official Records, South
0(0)02'50" West 537.10 feet to the northerly line of Parcel 65 as described in
Certified Copy of said Final Decree recorded in Book 42894, page 361 of said
Official Records; thence along said northerly line South 89(0)57'10" East 1.00
feet to the easterly line of said Parcel 65; thence along said easterly line and
along the easterly line of Parcel 49 as described in certified copy of said
Final Decree recorded in Book 37633, page 338 of said
<PAGE>

                                       21

Official Records, South 0(0)02'50" West 319.37 feet to said northerly line of
the southerly 17.00 feet of said Lot 603; thence along said last mentioned
northerly line North 89(0)59'20" East 138.98 feet to the point of beginning.


                        West Valley Division Headquarters

     Lot 19 of Tract No. 26561 in the City of Los Angeles, in the County of Los
Angeles, State of California, as per map recorded in Book 931, pages 86 to 91
inclusive of Maps, in the office of the County Recorder of said County.

     Excepting therefrom all oil, gas and other hydrocarbon and mineral
substances lying not less than five hundred (500) feet below the surface of said
real property, provided that grantor, its successors and assigns, shall not have
the right to go upon the surface of said real property for the purpose of
extracting said oil, gas, or other hydrocarbon and mineral substances, nor for
any purpose in connection therewith, but shall have the right to extract and
remove said oil, gas and other hydrocarbon and mineral substances by means of
slant-drilled wells located on adjacent or nearby land, or by any other means
which shall not require entry upon the surface of said real property, as
reserved in that deed recorded December 30, 1986 as Instrument No. 86-1821128 of
Official Records.


                       South Coastal Division Headquarters

     Parcel 2, in the City of Torrance, County of Los Angeles, State of
California, as shown on Parcel Map No. 19013 filed in Book 202, Pages 51 to 55,
inclusive, of Parcel Maps in the office of the County Recorder of said County.

     EXCEPTING THEREFROM, all minerals, petroleum, oil, asphaltum, gas and/or
hydrocarbon substances, including helium, within or underlying said parcel at a
depth of more than 500 feet below the surface as reserved by Santa Fe Energy
Company in that certain deed dated August 21, 1980, recorded September 16, 1980
as Document No. 80-895903, in the Office of the County Recorder of Los Angeles
County.


                            COUNTY OF SAN BERNARDINO

     Those certain lots, pieces and parcels of land and other property, rights,
and estates situate in the County of San Bernardino, State of California,
described as follows:
<PAGE>

                                       22

                             Chino Distribution Base

     The Northwest 1/4 of the Southeast 1/4 of the Southeast 1/4 of Section 11,
Township 2 South, Range 8 West, San Bernardino Base and Meridian, in the City of
Chino, according to Government Survey.

     Except the Westerly 25 feet as conveyed to the City of Chino, by Deed
recorded September 03, 1948 in Book 2268 Page 144, Official Records.

     Also except the South 1/2 thereof.


                               COUNTY OF RIVERSIDE

     Those certain lots, pieces and parcels of land and other property, rights,
and estates situate in the County of Riverside, State of California, described
as follows:


                           Temecula Distribution Base

     Parcel 2 of Parcel Map 15420, as per map recorded in Book 95, Pages 81 and
82 of Parcel Maps, in the office of the County Recorder of said County.