SECURITIES AND EXCHANGE COMMISSION
                              WASHINGTON, DC 20549

                                 SCHEDULE 13G
                                (Rule 13d-102)


             INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT
           TO RULES 13d-1(b)(c), AND (d) AND AMENDMENTS THERETO FILED
                           PURSUANT TO RULE 13d-2(b)

                         (Amendment No.____________)(1)


Orion Power Holdings, Inc.
--------------------------------------------------------------------------------
                                (Name of Issuer)


Common Stock
--------------------------------------------------------------------------------
                         (Title of Class of Securities)


686286105
--------------------------------------------------------------------------------
                                 (CUSIP Number)


December 31, 2001
--------------------------------------------------------------------------------
            (Date of Event Which Requires Filing of this Statement)


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

          [_]  Rule 13d-1(b)

          [_]  Rule 13d-1(c)

          [X]  Rule 13d-1(d)


----------
(1)  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 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).





CUSIP No.686286105                  13G                    Page 2 of 8 Pages


________________________________________________________________________________
1.   NAME OF REPORTING PERSONS
     I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY)
Constellation Energy Group, Inc.
52-1964611

________________________________________________________________________________
2.   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                 (a)  [_]
                                                                 (b)  [_]

________________________________________________________________________________
3.   SEC USE ONLY



________________________________________________________________________________
4.   CITIZENSHIP OR PLACE OF ORGANIZATION


Maryland
________________________________________________________________________________
  NUMBER OF    5.   SOLE VOTING POWER

   SHARES      17,205,900(1)
               _________________________________________________________________
BENEFICIALLY   6.   SHARED VOTING POWER

  OWNED BY     0
               _________________________________________________________________
    EACH       7.   SOLE DISPOSITIVE POWER

  REPORTING    17,205,900(1)
               _________________________________________________________________
   PERSON      8.   SHARED DISPOSITIVE POWER

    WITH       0
________________________________________________________________________________
9.   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON


17,205,900(1)
________________________________________________________________________________
10.  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*

                                                                          [_]

________________________________________________________________________________
11.  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9


16.5%
________________________________________________________________________________
12.  TYPE OF REPORTING PERSON*


CO
________________________________________________________________________________
                     *SEE INSTRUCTIONS BEFORE FILLING OUT!
(1) Represents common stock held by wholly owned subsidiaries, Constellation
    Holdings, Inc. and Constellation Real Estate, Inc. and includes warrant
    for 705,900 shares held by Constellation Holdings, Inc. which is presently
    exercisable.


CUSIP No.686286105                  13G                    Page 3 of 8 Pages


________________________________________________________________________________
1.   NAME OF REPORTING PERSONS
     I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY)
Constellation Holdings, Inc.*
52-1337857

________________________________________________________________________________
2.   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                 (a)  [_]
                                                                 (b)  [_]

________________________________________________________________________________
3.   SEC USE ONLY



________________________________________________________________________________
4.   CITIZENSHIP OR PLACE OF ORGANIZATION


Maryland
________________________________________________________________________________
  NUMBER OF    5.   SOLE VOTING POWER

   SHARES      0
               _________________________________________________________________
BENEFICIALLY   6.   SHARED VOTING POWER

  OWNED BY     10,705,900(1)
               _________________________________________________________________
    EACH       7.   SOLE DISPOSITIVE POWER

  REPORTING    0
               _________________________________________________________________
   PERSON      8.   SHARED DISPOSITIVE POWER

    WITH       10,705,900(1)
________________________________________________________________________________
9.   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON


10,705,900(1)
________________________________________________________________________________
10.  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*

                                                                          [_]

________________________________________________________________________________
11.  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9


10.3%
________________________________________________________________________________
12.  TYPE OF REPORTING PERSON*


CO
________________________________________________________________________________
                     *SEE INSTRUCTIONS BEFORE FILLING OUT!
(1) Includes warrant for 705,900 shares which is presently exercisable.
*   Constellation Holdings, Inc. acquired these shares on December 21, 2001
    from its affiliate Constellation Enterprises, Inc.



CUSIP No.686286105                  13G                    Page 4 of 8 Pages


________________________________________________________________________________
1.   NAME OF REPORTING PERSONS
     I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY)
Constellation Real Estate, Inc.*
52-1237835

________________________________________________________________________________
2.   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                 (a)  [_]
                                                                 (b)  [_]

________________________________________________________________________________
3.   SEC USE ONLY



________________________________________________________________________________
4.   CITIZENSHIP OR PLACE OF ORGANIZATION


Maryland
________________________________________________________________________________
  NUMBER OF    5.   SOLE VOTING POWER

   SHARES      0
               _________________________________________________________________
BENEFICIALLY   6.   SHARED VOTING POWER

  OWNED BY     6,500,000
               _________________________________________________________________
    EACH       7.   SOLE DISPOSITIVE POWER

  REPORTING    0
               _________________________________________________________________
   PERSON      8.   SHARED DISPOSITIVE POWER

    WITH       6,500,000
________________________________________________________________________________
9.   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON


6,500,000
________________________________________________________________________________
10.  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*

                                                                          [_]

________________________________________________________________________________
11.  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9


6.2%
________________________________________________________________________________
12.  TYPE OF REPORTING PERSON*


CO
________________________________________________________________________________
                     *SEE INSTRUCTIONS BEFORE FILLING OUT!
* Constellation Real Estate, Inc. acquired these shares on December 21, 2001
  from its affiliate Constellation Enterprises, Inc.



CUSIP No.686286105                     13G                    Page 5 of 8 Pages



Item 1(a).  Name of Issuer:


            Orion Power Holdings, Inc.
            ____________________________________________________________________

Item 1(b).  Address of Issuer's Principal Executive Offices:

            7 East Redwood Street, 10th Floor
            Baltimore, MD  21202
            ____________________________________________________________________

Item 2(a).  Name of Person Filing:
            Constellation Energy Group, Inc.
            Constellation Holdings, Inc.
            Constellation Real Estate, Inc.
            ____________________________________________________________________

Item 2(b).  Address of Principal Business Office, or if None, Residence:

            250 W. Pratt Street, Baltimore, MD  21201

            ____________________________________________________________________

Item 2(c).  Citizenship:

            Maryland

            ____________________________________________________________________

Item 2(d).  Title of Class of Securities:

            Common Stock

            ____________________________________________________________________

Item 2(e).  CUSIP Number:

            686286105

            ____________________________________________________________________

Item 3.     If This Statement  is Filed  Pursuant to  Rule 13d-1(b), or 13d-2(b)
            or (c), Check Whether the Person Filing is a:

     (a)  [_]  Broker or dealer registered under Section 15 of the Exchange Act.

     (b)  [_]  Bank as defined in Section 3(a)(6) of the Exchange Act.

     (c)  [_]  Insurance  company as defined in Section 3(a)(19) of the Exchange
               Act.

     (d)  [_]  Investment  company  registered under Section 8 of the Investment
               Company Act.

     (e)  [_]  An investment adviser in accordance with Rule 13d-1(b)(1)(ii)(E);

     (f)  [_]  An employee  benefit plan or endowment  fund in  accordance  with
               Rule 13d-1(b)(1)(ii)(F);

     (g)  [_]  A parent  holding  company or control  person in accordance  with
               Rule 13d-1(b)(1)(ii)(G);

     (h)  [_]  A savings  association  as defined in Section 3(b) of the Federal
               Deposit Insurance Act;

     (i)  [_]  A  church  plan  that  is  excluded  from  the  definition  of an
               investment  company  under  Section  3(c)(14)  of the  Investment
               Company Act;

     (j)  [_]  Group, in accordance with Rule 13d-1(b)(1)(ii)(J).





CUSIP No.686286105                   13G                    Page 6 of 8 Pages


Item 4.  Ownership.

     Provide  the  following  information  regarding  the  aggregate  number and
percentage of the class of securities of the issuer identified in Item 1.

     (a)  Amount beneficially owned:
          see below
          ______________________________________________________________________

     (b)  Percent of class:
          see below
          ______________________________________________________________________

     (c)  Number of shares as to which such person has:

          (i)   Sole power to vote or to direct the vote_______________________,


          (ii)  Shared power to vote or to direct the vote_____________________,


          (iii) Sole power to dispose or to direct the disposition of__________,


          (iv)  Shared power to dispose or to direct the disposition of________

                Constellation Energy Group, Inc. beneficially owns through its
                wholly owned subsidiaries 17,205,900 shares of common stock,
                which includes a warrant for 705,900 shares which is presently
                exercisable.  This represents 16.5% of issuer's common stock.
                Constellation Energy Group, Inc. has sole power to vote or to
                direct the vote of 17,205,900 shares and sole power to dispose
                or to direct the disposition of 17,205,900 shares.

                Constellation Holdings, Inc. is a wholly owned subsidiary of
                Constellation Energy Group, Inc. and owns 10,705,900 shares of
                common stock, which includes a warrant for 705,900 shares which
                is presently exercisable.  This represents 10.3% of issuer's
                common stock.  Constellation Holdings, Inc. has shared power
                to vote or to direct the vote of 10,705,900 shares and shared
                power to dispose or to direct the disposition of 10,705,900
                shares.

                Constellation Real Estate, Inc. is an indirect wholly owned
                subsidiary of Constellation Energy Group, Inc. and owns
                6,500,000 shares of common stock.  This represents 6.2% of
                issuer's common stock.  Constellation Real Estate, Inc. has
                shared power to vote or to direct the vote of 6,500,000 shares,
                and shared power to dispose or to direct the disposition of
                6,500,000 shares.
         _______________________________________________________________________

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 [ ].

         N/A
         _______________________________________________________________________

Item 6.  Ownership of More Than Five Percent on Behalf of Another Person.
         Constellation Energy Group, Inc. is the beneficial owner of 16.5% of
         Orion Power Holdings, Inc.'s common stock because its wholly owned
         subsidiaries, Constellation Holdings, Inc. and Constellation Real
         Estate, Inc. are the owners of 17,205,900 shares of common stock,
         which included a warrant for 705,900 shares which is presently
         exercisable.
         _______________________________________________________________________

Item 7.  Identification and  Classification of the Subsidiary Which Acquired the
         Security  Being  Reported on by the Parent  Holding  Company or Control
         Person.

         N/A

         _______________________________________________________________________

Item 8.  Identification  and  Classification  of Members of the Group.

         N/A

         _______________________________________________________________________




CUSIP No.686286105                   13G                    Page 7 of 8 Pages


Item 9.  Notice of Dissolution of Group.

         N/A

          ______________________________________________________________________

Item 10.  Certifications.

     (a)  The  following  certification  shall be included if the  statement  is
          filed pursuant to Rule 13d-1(b):

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


     (b)  The  following  certification  shall be included if the  statement  is
          filed pursuant to Rule 13d-1(c):

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

          N/A


CUSIP No.686286105                   13G                    Page 8 of 8 Pages


                                    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.

                                                       2/12/02
                                        ----------------------------------------
                                                        (Date)

                                          /s/ David A. Brune
                                        ----------------------------------------
                                                      (Signature)
                                        David A. Brune/Vice President,
                                        Secretary and General Counsel
                                        Constellation Energy Group, Inc.
                                        ----------------------------------------
                                                      (Name/Title)




                                                       2/12/02
                                        ----------------------------------------
                                                        (Date)

                                          /s/ Dan A. Skowronski
                                        ----------------------------------------
                                                      (Signature)
                                        Dan A. Skowronski/Secretary
                                        Constellation Holdings, Inc.
                                        ----------------------------------------
                                                      (Name/Title)


                                                       2/12/02
                                        ----------------------------------------
                                                        (Date)

                                           /s/ Donna M. Levy
                                        ----------------------------------------
                                                      (Signature)
                                        Donna M. Levy/Secretary
                                        Constellation Real Estate, Inc.
                                        ----------------------------------------
                                                      (Name/Title)


Note.  Schedules  filed in paper format shall include a signed original and five
copies of the schedule, including all exhibits. See Rule 13d-7 for other parties
for whom copies are to be sent.

Attention.  Intentional  misstatements  or omissions of fact constitute  federal
criminal violations (see 18 U.S.C. 1001).