Exhibit 5

        [LETTERHEAD OF KRAMER, LEVIN, NAFTALIS & FRANKEL APPEARS HERE]



                                 June 27, 1997



Long Island Lighting Company
175 East Old Country Road
Hicksville, New York 11801

            Re:  Registration Statement on Form S-4
                 (Registration No. 333-18025)
                 ------------------------------------------

Ladies and Gentlemen:

            We have acted as counsel to Long Island Lighting Company, a New York
corporation ("LILCO"), in connection with the preparation and filing of the 
above-captioned Registration Statement on Form S-4 (the "Registration 
Statement") under the Securities Act of 1933, as amended (the "Securities Act"),
relating to (i) the proposed issuance by BL Holding Corp., a corporation to be 
formed under the laws of New York (the "Holding Company"), of shares of common 
stock, par value $0.01 per share ("Holding Company Common Stock"), of the 
Holding Company (the "Holding Company Common Shares") to the holders of shares 
of LILCO common stock (the "LILCO Common Shares") pursuant to the Amended and 
Restated Agreement and Plan of Exchange and Merger dated as of June 26, 1997 
(the "Combination Agreement") among LILCO, the Holding Company and The Brooklyn 
Union Gas Company, a New York corporation, and (ii) the proposed issuance by the
Holding Company of shares of Series AA preferred stock, par value $25 per share 
("Series AA Preferred Stock"), of the Holding Company (the "Holding Company 
Preferred Shares") to the holders of shares of LILCO Series AA preferred stock 
(the "LILCO Preferred Shares") pursuant to the Agreement and Plan of Merger 
dated as of June 26, 1997 (the "Merger Agreement") among LILCO, the Holding 
Company, the Long Island Power Authority, a corporate municipal instrumentality 
and political subdivision of the State of New York, and LIPA Acquisition 
Corporation, a corporation to be formed under the laws of New York.

            As such counsel, we have examined such corporate records, 
certificates and other documents and such questions of law as we have considered
necessary or appropriate for the purposes of this opinion. In rendering this 
opinion, we have (a) assumed (i) the genuineness of all signatures on all 
documents examined by us, (ii) the authenticity of all documents submitted to us
as originals, and (iii) the conformity to original documents of all documents 
submitted to us as photostatic or conformed copies and the authenticity of the 


 
 
[LETTERHEAD OF KRAMER, LEVIN, NAFTALIS & FRANKEL APPEARS HERE]


Long Island Lighting
June 27, 1997
Page 2


originals of such copies; and (b) relied on (i) certificates of public officials
and (ii) as to matters of fact, statements and certificates of officers of the 
Company and the Holding Company.

      We are attorneys admitted to the Bar of the State of New York, and we 
express no opinion as to the laws of any other jurisdiction other than the laws 
of the United States of America.

      Based upon the foregoing, we are of the opinion that:

      1.   The Holding Company Common Shares, when issued or distributed in the 
manner set forth in the Combination Agreement or the Merger Agreement, as 
applicable, will have been duly authorized and will constitute validly issued 
and, except to the extent otherwise provided under Section 630 of the New York 
Business Corporation Law, nonassessable shares of Holding Company Common Stock.

      2.   The Holding Company Preferred Shares, when issued and delivered in 
exchange for LILCO Preferred Shares in the manner set forth in the Merger 
Agreement, will have been duly authorized and will constitute validly issued 
and, except to the extent otherwise provided under Section 630 of the New York 
Business Corporation Law, nonassessable shares of Series AA Preferred Stock.

      We consent to the filing of this opinion as an exhibit to the Registration
Statement and to the use of our name under the heading "Legal Matters" in the 
prospectus forming a part of the Registration Statement. In giving such consent 
we do not thereby concede that we are within the category of persons whose 
consent is required under Section 7 of the Securities Act or the rules and 
regulations promulgated thereunder.


                                      Very truly yours,


                                      /s/ Kramer, Levin, Naftalis & Frankel

                                      Kramer, Levin, Naftalis & Frankel