Page 1 of 5 Pages

                                   UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                            WASHINGTON, D.C.  20549

                                   SCHEDULE 13G

                   Under the Securities exchange Act of 1934



                           CONSTELLATION ENER
             -----------------------------------------------------
                              (NAME OF ISSUER)

                                  COM
             -----------------------------------------------------
                       (TITLE OF CLASS OF SECURITIES)

                                 210371100
             -----------------------------------------------------
                              (CUSIP NUMBER)

                           December 31, 2010
             -----------------------------------------------------
            (Date of event which requires filing of this Statement)

  Check the appropriate box to designate the rule pursuant to which
  this Schedule is filed:

    X  Rule 13d-1(b)
       Rule 13d-1(c)
       Rule 13d-1(d)

  * The remainder of this cover page shall be filled out for a reporting
  person's initial filing on this form with respect to the subject class
  of securities, and for any subsequent amendment containing information
  which would alter the disclosures provided in a prior cover page.

  The information required in the remainder of this cover page shall not
  be deemed to be 'filed' for the purpose of Section 18 of the Securities
  Exchange Act of 1934 ('Act') or otherwise subject to the liabilities
  of that section of the Act but shall be subject to all other provisions
  of the Act (however, see the Notes).

                       (CONTINUED ON FOLLOWING PAGE(S))





                                   13G                      Page 4 of 5 Pages


Item 4. Ownership as of 12/31/2010

      (a) Amount Beneficially Owned:  15,482,500  shares of common stock
          acquired solely for investment purposes on behalf of client
          discretionary investment advisory accounts*

      (b) Percent of Class:  7.7%

      (c) Deemed Voting Power and Disposition Power:



                        (i)           (ii)          (iii)         (iv)
                        Deemed        Deemed        Deemed        Deemed
                        to have       to have       to have       to have
                        Sole Power    Shared Power  Sole Power    Shared Power
                        to Vote       to Vote       to Dispose    to Dispose
                        or to         or to         or to         or to
                        Direct        Direct        Direct the    Direct the
                        the Vote      the Vote      Disposition   Disposition
                        ------------  ------------  ------------  ------------
                                                      


AllianceBernstein         12,650,155             0    15,471,272        11,228



*AllianceBernstein L.P. is a majority owned subsidiary of AXA Financial, Inc.
and an indirect majority owned subsidiary of AXA SA.  AllianceBernstein
operates under independent management and makes independent decisions from
AXA and AXA Financial and their respective subsidiaries and AXA and AXA
Financial calculate and report beneficial ownership separately from
AllianceBernstein pursuant to guidance provided by the Securities and
Exchange Commission in Release Number 34-39538 (January 12, 1998).

AllianceBernstein may be deemed to share beneficial ownership with AXA reporting
persons by virtue of 11,228 shares of common stock acquired on behalf of the
general and separate accounts of the affiliated entities for which
AllianceBernstein serves as a subadvisor. Each of AllianceBernstein and the AXA
entities reporting herein acquired their shares of common stock for investment
purposes in the ordinary course of their investment management and insurance



                                                             Page 5 of 5 Pages

Item 5. Ownership of Five Percent or Less of a Class:
        If this statement is being filed to report the fact that as of the date
        hereof the reporting person has ceased to be the beneficial owner of
        more than five percent of the class of securities, check the following.

                                                                          [ ]

Item 6. Ownership of More than Five Percent on behalf of Another Person.  N/A

Item 7. Identification and Classification of the Subsidiary which Acquired
        the Security Being Reporting on by the Parent Holding Company:    N/A



Item 8. Identification and Classification of Members of the Group.      N/A

Item 9.  Notice of Dissolution of Group:                                N/A

Item 10. Certification:

         By signing below I certify that to the best of my knowledge and
    belief, the securities referred to above were acquired in the ordinary
    course of business and were not acquired for the purpose of and do not
    have the effect of changing or influencing the control of the issuer
    of such securities and were not acquired in connection with or as a
    participant in any transaction having such purposes or effect.



         Signature

         After reasonable inquiry and to the best of my knowledge and
    belief, I certify that the information set forth in this statement
    is true, complete and correct.








    Date:  02/09/2011, ALLIANCEBERNSTEIN L.P.







                               /s/ Laurence Bertan

                            Name:  Laurence Bertan
                            Title: SVP and Head of Regulatory Reporting