EXHIBIT 5

                                                                    July 1, 1999




Indiana Gas Company, Inc.
1630 North Meridian Street
Indianapolis, IN 46202

Dear Gentlemen:

     You  have  requested  our  opinion  in  connection  with  the  Registration
Statement  on Form S-3 (the  "Registration  Statement")  of Indiana Gas Company,
Inc.,  an  Indiana  corporation  (the  "Corporation"),  filed  pursuant  to  the
Securities Act of 1933, as amended ("Securities Act"), relating to the offer and
sale by the  Corporation of up to  $100,000,000  of debt  securities  (the "Debt
Securities") to be issued and sold under the provisions of the Indenture between
the  Corporation  and U. S. Bank Trust National  Association,  formerly known as
First Trust  National  Association,  which was formerly known as Bank of America
Illinois,  which was formerly known as Continental Bank,  National  Association,
dated as of February 1, 1991, as supplemented and amended and to be supplemented
and amended for the purpose of creating the series of Debt  Securities.  We have
examined  such  records,  certificates  and other  documents  and have made such
investigation of law as we have deemed necessary in the circumstances.

     Based on that examination and  investigation,  it is our opinion that, when
the Debt Securities have been issued and sold and the purchase price thereof has
been paid in  accordance  with the  transactions  proposed  in the  Registration
Statement,  as the same may be amended, and when the steps mentioned in the next
paragraph  have  been  taken,  and the Debt  Securities  shall  have  been  duly
executed,  authenticated  and delivered in accordance  with the  Indenture,  and
delivered against payment  therefore,  the Debt Securities will be legal,  valid
and binding obligations of the Corporation.

     The steps to be taken which are referred to in the preceding paragraph are:

          1.  Appropriate  definitive  action by the Board of  Directors  of the
     Corporation or an authorized committee thereof with respect to the proposed
     transactions set forth in the Registration Statement;

          2. Compliance with the Securities Act,  applicable state blue sky laws
     and the Trust Indenture Act of 1939, as amended; and


Indiana Gas Company, Inc.
Page Two
July 1, 1999



          3. Issuance and sale of the Debt  Securities  in  accordance  with the
     corporate authorization aforesaid.

     This  opinion  letter is limited to the current  Federal laws of the United
States and the current  internal  laws of the State of Indiana  (without  giving
effect to any conflict of law  principles  thereof) and we have not  considered,
and express no opinion on, the laws of any other jurisdiction.

     We consent to the use of our name under the caption "Legal Opinions" in the
Prospectus  included  in the  Registration  Statement  and to the filing of this
opinion as Exhibit 5 to the Registration Statement.

                                                      Very truly yours,


                                                          BARNES & THORNBURG
                                                      /s/ BARNES & THORNBURG