EXHIBIT 5.1 
                       MURTHA, CULLINA, RICHTER AND PINNEY 
                         CityPlace I - 185 Asylum Street 
                        Hartford, Connecticut 06103-3469 
                              Phone (860) 240-6000 
                               Fax  (860) 240-6150 
    
    
                                December 27, 1996 
    
    
    
   CTG Resources, Inc. 
   100 Columbus Boulevard 
   Hartford, CT 06103 
    
   Ladies and Gentlemen: 
    
        We have acted as counsel to CTG Resources, Inc., a Connecticut corpora-
   tion (the "Company"), in connection with the preparation and filing of the
   Company's Registration Statement on Form S-4 filed with the Securities and
   Exchange Commission (the "Commission") on November 18, 1996 and amended by
   Amendment No. 1 thereto filed with the Commission on December 27, 1996 (as
   amended, the Registration Statement"), relating to the registration under
   the Securities Act of 1933, as amended (the "Securities Act"), of 10,634,329
   shares (the "Shares") of the common stock, without par value, of the Company
   ("CTG Common Stock").  This opinion is furnished to you in accordance with
   the requirements of Item 601(b)(5) of Regulation S-K promulgated under the
   Securities Act. 
    
        In connection with this opinion, we have reviewed and relied upon
   originals or copies, certified or otherwise authenticated to our
   satisfaction, of the following: (i) the Registration Statement; (ii) the
   Certificate of Incorporation and Bylaws of the Company as currently in
   effect; (iii) the Agreement and Plan of Exchange (the "Exchange Agreement")
   between the Company and Connecticut Natural Gas Corporation, a Connecticut
   corporation ("CNG") attached as Exhibit A to the Prospectus/Proxy Statement
   forming a part of the Registration Statement; (vii) the Amended and Restated
   Certificate of Incorporation and Bylaws of the Company that are to be
   approved and in effect prior to the exchange contemplated by the Exchange
   Agreement (the "Exchange"); (viii) certain resolutions adopted, or proposed
   to be adopted, by the Board of Directors of the Company relating to
   transactions contemplated by the Registration Statement; and (ix) such other
   records, documents and instruments as we have deemed necessary or appro-
   priate in order to express the opinions hereinafter set forth. 
    
        We have assumed, with your consent, that (i) the exchange contemplated
   by the Exchange Agreement (the "Exchange") will be effected in accordance
   with the Exchange Agreement and the laws of the State of Connecticut and in
   the manner described in the Registration Statement, (ii) all the provisions
   of the Exchange Agreement will be complied with, (iii) the Exchange
   Agreement and the Prospectus/Proxy Statement describe the entire transaction
   and all related transactions, (iv) the facts and representations made to us
   by officers and directors of the Company are true and correct, (v) the





   CTG Resources, Inc.
   December 27, 1996
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   proposed resolutions to be adopted by the Board of Directors of the Company
   will be duly approved and adopted prior to the effective date of the
   Exchange, and (vi) there will be no change in any of the facts or
   representations material to this opinion between the date of this opinion
   and the effective time of the Exchange. 
    
        Based upon and subject to the forgoing, we are of the opinion that, if
   and when the Registration Statement is declared effective by the Commission
   and the proposed Exchange is consummated in the manner contemplated by the
   Exchange Agreement, the CTG Common Stock issued in exchange for shares of
   the common stock, par value $3.125 per share, of CNG, will be validly
   issued, fully paid and nonassessable. 
    
        We hereby consent to the filing of this opinion with the Commission as
   Exhibit 5.1 to the Registration Statement.  We further consent to the use of
   the name of this firm in the Registration Statement and under the heading
   "Legal Opinions" in the Prospectus/Proxy Statement forming a part thereof. 
   In giving this consent, we do not thereby admit that we are within the
   category of persons whose consent is required pursuant to Section 7 of the
   rules and regulations of the Commission. 
    
                                    Very truly yours, 
    
                                    Murtha, Cullina, Richter and Pinney 
    
    
    
                                    By:_______________________________         
                                       Dwight A. Johnson 
                                       A Partner Thereof