Exhibit
      5





Opinion
      of Fleischman and Walsh, L.L.P.





FLEISCHMAN
      AND WALSH, L.L.P.


1919
      Pennsylvania Avenue, NW


Sixth
      Floor


Washington,
      D.C. 20006


(202)
      939-7900




October
      13, 2006







Southern
      Union Company


5444
      Westheimer Road


Houston,
      Texas 77056




Ladies
      and Gentlemen:





We
      have
      acted as counsel to Southern Union Company, a Delaware corporation (the
“Company”), in connection with the automatic shelf registration statement on
      Form S-3 (the “Registration Statement”) being filed by the Company with the
      Securities and Exchange Commission pursuant to the Securities Act of 1933,
      as
      amended (the “Securities Act”), for the registration of the sale from time to
      time of the following securities:





·
            Common
                stock, $1.00 par value, of the Company (“Common
                Stock”);




·
            Preferred
                stock, no par value, of the Company (“Preferred Stock” and, together with
                the Common Stock, “Equity
                Securities”);




·
            Senior
                debt securities of the Company (“Senior Debt
                Securities”);




·
            Subordinated
                debt securities of the Company (“Subordinated Debt Securities” and,
                together with the Senior Debt Securities, “Debt
                Securities”);




·
            Stock
                purchase contracts of the Company for the purchase of either Common
                Stock
                or Preferred Stock (“Stock Purchase
                Contracts”);




·
            Common
                Stock and Preferred Stock that may be issued upon exercise of the
                Stock
                Purchase Contracts;




·
            Stock
                purchase units of the Company, consisting of a Stock Purchase Contract
                and
                either (1) Debt Securities, or (2) debt obligations of third parties,
                including U.S. Treasury securities (“Stock Purchase
                Units”);




·
            Debt
                purchase contracts of the Company for the purchase of Debt Securities
                (“Debt Purchase Contracts” and together with the Stock Purchase Contracts,
                “Securities Purchase Contracts”);




·
            Debt
                Securities that may be issued upon exercise of the Debt Purchase
                Contracts;




·
            Debt
                purchase units of the Company, consisting of a Debt Purchase Contract
                and
                either (1) Debt Securities, or (2) debt obligations of third parties,
                including U.S. Treasury securities (“Debt Purchase Units” and, together
                with the Stock Purchase Units, “Securities Purchase
                Units”);




·
            Warrants
                of the Company to purchase Common Stock, Preferred Stock or Debt
                Securities (“Warrants”);




·
            Common
                Stock, Preferred Stock and Debt Securities that may be issued upon
                exercise of the Warrants; and




·
            Depositary
                shares of the Company, each representing a fraction of a share of
                a
                particular class of Preferred Stock (the “Depositary
                Shares”).





The
      Common Stock, Preferred Stock, Debt Securities, Securities Purchase Contracts,
      Securities Purchase Units, Warrants and Depositary Shares are hereinafter
      referred to collectively as the “Securities.”








The
      Senior Debt Securities will be issued pursuant to the Indenture, dated January
      31, 1994, as supplemented, between the Company and JP Morgan Chase Bank, as
      trustee (in such capacity, the “Senior Trustee”), and/or one or more additional
      senior debt securities indentures, each as supplemented, between the Company
      and
      the trustee named in each (collectively, the “Senior Indentures”).





The
      Subordinated Debt Securities will be issued pursuant to the Subordinated Debt
      Securities Indenture, dated May 10, 1995, between the Company and JP Morgan
      Chase Bank, as trustee (in such capacity, the “Subordinated Trustee”), and/or
      one or more additional subordinated debt securities indentures, each as
      supplemented, between the Company and the trustee named in each (collectively,
      the “Subordinated Indentures” and together with the Senior Indentures, the
“Indentures”).





The
      Securities Purchase Contracts will be issued pursuant to one or more securities
      contract purchase agreements (each, a “Securities Contract Purchase Agreement”)
      between the Company and the agent named therein.





The
      Securities Purchase Units will be issued pursuant to a one or more securities
      unit purchase agreements (each, a “Securities Unit Purchase Agreement”) between
      the Company and the agent named therein.





The
      Warrants will be issued pursuant to one or more warrant agreements (each, a
      “Warrant Agreement”) between the Company and the warrant agent named
      therein.





The
      Depositary Shares will be evidenced by depositary receipts issued pursuant
      to
      one or more deposit agreements (each, a “Deposit Agreement”) between the Company
      and the depositary named therein.





We
      have
      examined the Registration Statement and the documents filed as exhibits thereto
      with the Securities and Exchange Commission. We also have examined the
      originals, or duplicates or certified or conformed copies, of such records,
      agreements, instruments and other documents and have made such other and further
      investigations as we have deemed relevant and necessary in connection with
      the
      opinions expressed herein. As to questions of fact material to this opinion,
      we
      have relied upon certificates of public officials and of officers and
      representatives of the Company.





In
      rendering the opinions set forth below, we have assumed the genuineness of
      all
      signatures, the legal capacity of natural persons, the authenticity of all
      documents submitted to us as originals, the conformity to original documents
      of
      all documents submitted to us as duplicates or certified or conformed copies
      and
      the authenticity of the originals of such latter documents. We also have assumed
      that:





A.  at
      any
      time the Company issues Securities, such entity will be validly existing and
      in
      good standing under the laws of the State of Delaware, the Registration
      Statement shall be effective and such effectiveness shall not have been
      terminated or rescinded, and there shall not have occurred any change in law
      affecting the validity or enforceability of such Securities from the date hereof
      until the time of their issuance;





B.  at
      any
      time the Company issues Securities, the Board of Directors of the Company shall
      have duly established the terms of such Securities and duly authorized the
      issuance and sale of such Securities, and such authorization shall not have
      been
      modified or rescinded;





C.  none
      of
      the terms of any Security to be established subsequent to the date hereof,
      nor
      the issuance and delivery of such Security, nor the compliance by the issuer
      thereof with the terms of such Security, will violate any applicable law or
      will
      result in a violation of any provision of any instrument or agreement then
      binding upon such issuer, or any restriction imposed by any court or
      governmental body having jurisdiction over such issuer;





D.  the
      Senior Indenture is now, and at the time of execution, authentication, issuance
      and delivery of any Senior Debt Securities will be, the valid and legally
      binding obligation of the Senior Trustee;





E.  the
      Subordinated Indenture is now, and at the time of execution, authentication,
      issuance and delivery of any Subordinated Debt Securities will be, the valid
      and
      legally binding obligation of the Subordinated Trustee;








F.  at
      the
      time of execution, authentication, issuance and delivery of any Securities
      Purchase Contracts, the applicable Securities Contract Purchase Agreement will
      be the valid and legally binding obligation of the agent named therein;





G.  at
      the
      time of execution, issuance and delivery of any Securities Purchase Units,
      the
      applicable Securities Unit Purchase Agreement will be the valid and legally
      binding obligation of the agent named therein;





H.  at
      the
      time of execution, issuance and delivery of any Warrant, the applicable Warrant
      Agreement will be the valid and legally binding obligation of the warrant agent
      named therein; and





I.  at
      the
      time of execution, issuance and delivery of any Depositary Shares, the
      applicable Deposit Agreement will be the valid and legally binding obligation
      of
      the depositary named therein.





We,
      as
      your counsel, have examined originals or copies, certified or otherwise
      identified to our satisfaction, of such documents, corporate records,
      certificates of public officials and other instruments as we have deemed
      necessary or advisable for the purposes of rendering this opinion.





Based
      upon the foregoing, and subject to the qualifications and limitations stated
      herein, we are of the opinion that:





1.  With
      respect to the Common Stock, when the Common Stock has been duly issued and
      delivered upon payment therefore in accordance with the applicable underwriting
      or other agreement, and upon compliance with applicable regulatory requirements,
      the Common Stock will be validly issued, fully paid and nonassessable.





2.  With
      respect to the Preferred Stock, when the Preferred Stock has been duly issued
      and delivered upon payment therefore in accordance with the applicable
      underwriting or other agreement, and upon compliance with applicable regulatory
      requirements, the Preferred Stock will be validly issued, fully paid and
      nonassessable.





3.  With
      respect to the Debt Securities, when a particular series of Debt Securities
      have
      been duly authorized, executed, authenticated, issued and delivered upon payment
      therefore in accordance with the applicable Indenture and the applicable
      underwriting or other agreement, and upon compliance with applicable regulatory
      requirements, such Debt Securities will constitute valid and binding obligations
      of the Company, enforceable in accordance with their terms, except as (a) the
      enforceability thereof may be limited by bankruptcy, insolvency, reorganization,
      fraudulent transfer, moratorium or similar laws now or hereinafter in effect
      relating to or affecting the enforcement of creditors’ rights generally and (b)
      the availability of equitable remedies may be limited by equitable principles
      of
      general applicability (regardless of whether considered in a proceeding at
      law
      or in equity).





4.  With
      respect to the Securities Purchase Contracts, when the Securities Contract
      Purchase Agreement to be entered into in connection with the issuance of any
      Securities Purchase Contracts has been duly authorized, executed and delivered
      by the agent named therein and the Company; the specific terms of the Securities
      Purchase Contracts have been duly authorized and established in accordance
      with
      such Securities Contract Purchase Agreement; the issuance of any Common Stock
      underlying such Securities Purchase Contracts has been authorized in the manner
      contemplated by paragraph 1 above; the issuance of any Preferred Stock
      underlying such Securities Purchase Contracts has been authorized in the manner
      contemplated by paragraph 2 above; the issuance of any Debt Securities
      underlying such Securities Purchase Contracts has been authorized in the manner
      contemplated by paragraph 3 above; and such Securities Purchase Contracts have
      been duly authorized, executed, issued and delivered upon payment therefore
      in
      accordance with such Securities Contract Purchase Agreement and the applicable
      underwriting or other agreement, and upon compliance with applicable regulatory
      requirements, such Securities Purchase Contracts will constitute valid and
      binding obligations of the Company, enforceable in accordance with their terms,
      except as (a) the enforceability thereof may be limited by bankruptcy,
      insolvency, reorganization, fraudulent transfer, moratorium or similar laws
      now
      or hereinafter in effect relating to or affecting the enforcement of creditors’
rights generally and (b) the availability of equitable remedies may be limited
      by equitable principles of general applicability (regardless of whether
      considered in a proceeding at law or in equity).





5.  With
      respect to the Securities Purchase Units, when the Securities Unit Purchase
      Agreement to be entered into in connection with the issuance of any Securities
      Purchase Units has been duly authorized, executed and delivered by the agent
      named therein and the Company; the specific terms of the Securities Purchase
      Units have been duly authorized and established in accordance with such
      Securities Unit Purchase Agreement; any Securities




Purchase
        Contracts comprising a part of such Securities Purchase Units have been
        authorized, executed, issued and delivered in the manner contemplated by
        paragraph 6 above; the issuance of any Common Stock underlying such Securities
        Purchase Contracts has been authorized in the manner contemplated by paragraph
        1
        above; the issuance of any Preferred Stock underlying such Securities Purchase
        Contracts has been authorized in the manner contemplated by paragraph 2 above;
        the issuance of any Debt Securities underlying such Securities Purchase
        Contracts has been authorized in the manner contemplated by paragraph 3 above;
        any Debt Securities comprising a part of such Securities Purchase Units have
        been authorized, executed, issued and delivered in the manner contemplated
        by
        paragraph 3 above; any debt securities of other issuers comprising a part
        of
        such Securities Purchase Units have been delivered in accordance with such
        Securities Unit Purchase Agreement; and such Securities Purchase Units have
        been
        duly authorized, executed, issued and delivered upon payment therefore in
        accordance with such Securities Unit Purchase Agreement and the applicable
        underwriting or other agreement, and upon compliance with applicable regulatory
        requirements, such Securities Purchase Units will constitute valid and binding
        obligations of the Company, enforceable in accordance with their terms, except
        as (a) the enforceability thereof may be limited by bankruptcy, insolvency,
        reorganization, fraudulent transfer, moratorium or similar laws now or
        hereinafter in effect relating to or affecting the enforcement of creditors’
rights generally and (b) the availability of equitable remedies may be limited
        by equitable principles of general applicability (regardless of whether
        considered in a proceeding at law or in equity).





6.  With
      respect to the Warrants, when the Warrant Agreement to be entered into in
      connection with the issuance of any Warrants has been duly authorized, executed
      and delivered by the agent named therein and the Company; the specific terms
      of
      the Warrants have been duly authorized and established in accordance with such
      Warrant Agreement; the issuance of any Common Stock underlying such Warrants
      has
      been authorized in the manner contemplated by paragraph 1 above; the issuance
      of
      any Preferred Stock underlying such Warrants has been authorized in the manner
      contemplated by paragraph 2 above; the issuance of any Debt Securities
      underlying such Warrants has been authorized in the manner contemplated by
      paragraph 3 above; and such Warrants have been duly authorized, executed, issued
      and delivered upon payment therefore in accordance with such Warrant Agreement
      and the applicable underwriting or other agreement, and upon compliance with
      applicable regulatory requirements, such Warrants will constitute valid and
      binding obligations of the Company, enforceable in accordance with their terms,
      except as (a) the enforceability thereof may be limited by bankruptcy,
      insolvency, reorganization, fraudulent transfer, moratorium or similar laws
      now
      or hereinafter in effect relating to or affecting the enforcement of creditors’
rights generally and (b) the availability of equitable remedies may be limited
      by equitable principles of general applicability (regardless of whether
      considered in a proceeding at law or in equity).





7.  With
      respect to the Depositary Shares, when the Deposit Agreement to be entered
      into
      in connection with the issuance of any Depositary Shares has been duly
      authorized, executed and delivered by the agent named therein and the Company;
      the specific terms of a particular series of Depositary Shares have been duly
      authorized and established in accordance with the Deposit Agreement; the
      Preferred Stock underlying such Depositary Shares have been authorized,
      executed, issued and delivered to the agent in the manner contemplated by
      paragraph 2 above and in accordance with such Deposit Agreement; and such
      Depositary Shares have been duly authorized, executed, authenticated, issued
      and
      delivered upon payment therefore in accordance with such Deposit Agreement
      and
      the applicable underwriting or other agreement, and upon compliance with
      applicable regulatory requirements, such Depositary Shares will constitute
      valid
      and binding obligations of the Company, enforceable in accordance with their
      terms, except as (a) the enforceability thereof may be limited by bankruptcy,
      insolvency, reorganization, fraudulent transfer, moratorium or similar laws
      now
      or hereinafter in effect relating to or affecting the enforcement of creditors’
rights generally and (b) the availability of equitable remedies may be limited
      by equitable principles of general applicability (regardless of whether
      considered in a proceeding at law or in equity).





*
      *
      *


We
      are
      members of the Bar of the District of Columbia and the foregoing opinion is
      limited to the laws of the District of Columbia, the Delaware General
      Corporation Law, the Business Trust Act of the State of Delaware and the federal
      laws of the United States of America. For purposes of this opinion, we have
      with
      your permission assumed that the laws of the State of New York are identical
      in
      all respects with the laws of the District of Columbia.




We
      hereby
      consent to the filing of this opinion as an exhibit to the Registration
      Statement to above and further consent to the reference to our name under the
      caption “Validity of Securities” in the prospectus, which is




a
        part of
        the Registration Statement. In giving this consent, we do not admit that
        we are
        in the category of persons whose consent is required under Section 7 of the
        Securities Act.





This
      opinion is rendered solely to you in connection with the above matter. This
      opinion may not be relied upon by you for any other purpose or relied upon
      by or
      furnished to any other person without our prior written consent.





Sincerely
      yours,





/s/
      Fleischman and Walsh, L.L.P.





Fleischman and Walsh, L.L.P.