<PAGE>

                                                                    Exhibit 4.12


         THIS FOURTH AMENDMENT TO THE INDENTURE, dated as of October 16, 1998,
is entered into between PETROLEUM HEAT AND POWER CO., INC., a Minnesota
corporation (the "Company"), and THE CHASE MANHATTAN BANK (formerly known as
CHEMICAL BANK), a New York corporation (the "Trustee").

                               W I T N E S S E T H

         WHEREAS, the Company and the Trustee have entered into that certain
Indenture dated as of April 1, 1993, as amended as of January __, 1994, November
22, 1995 and December 4, 1996 (as amended, the "Indenture"), for the equal and
ratable benefit of the Holders of the Company's 10 1/8% Subordinated Notes Due
2003 (the "Securities"); and

         WHEREAS, in accordance with Section 9.02 of the Indenture the Company
has obtained the written consent of the Holders of at least 66 2/3% in principal
amount of the Securities to an amendment to the Indenture.

         NOW, THEREFORE, for the purpose of memorializing the amendment to the
Indenture so consented to by Holders of the Securities, the parties hereto do
hereby agree as follows:

         SECTION           1.       Definitions and Terms.

         Unless otherwise defined herein, all initially capitalized terms used
herein shall have the meanings assigned to such terms in the Indenture.

         SECTION           2.       Amendment to Indenture.

         Sections 4.03, 4.04, 4.05, 4.06, 4.07, 4.08, 4.09, 4.12 and 5.01 of the
Indenture shall be deleted in their entirety.


         SECTION           3.       Ratification of Indenture, as Amended.

         The Indenture, as amended hereby, is hereby ratified and confirmed and
continues in full force and effect.

         SECTION           4.       Effectiveness.

         This Fourth Amendment to the Indenture shall become effective upon the
execution hereof by the Company and the Trustee, the Company having delivered to
the Trustee evidence of consent from the Holders of at least a majority in
principal amount of the Securities then outstanding.



<PAGE>



         SECTION           5.       Recitals.

         The recitals contained herein shall be taken as the statements of the
Company and the Trustee assumes no responsibility for their correctness. The
Trustee makes no representations as to the validity or sufficiency of this
amendment.

         SECTION           6.       Governing Law.

         This amendment shall be governed by and construed in accordance with
the laws of the jurisdiction which govern the Indenture and its construction.

         SECTION           7.       Counterparts.

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




                                      - 2 -

<PAGE>


         IN WITNESS WHEREOF, the parties hereto have caused this Fourth
Amendment to the Indenture to be duly executed as of the date first above
written.

                                  PETROLEUM HEAT AND POWER CO., INC.



                                  By:                                  
                                     -----------------------------------
                                           Name:
                                           Title:
                                  
                                  
                                  THE CHASE MANHATTAN BANK, as Trustee
                                  
                                  
                                  
                                  By:
                                     -----------------------------------
                                           Name:
                                           Title:
                                  
                                  

                                      - 3 -