Ownership Submission
FORM 3
UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940
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(Print or Type Responses)
1. Name and Address of Reporting Person *
  Manasco Shon J.
2. Date of Event Requiring Statement (Month/Day/Year)
08/11/2009
3. Issuer Name and Ticker or Trading Symbol
CONSTELLATION ENERGY GROUP INC [CEG]
(Last)
(First)
(Middle)
100 CONSTELLATION WAY
4. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
_____ Director _____ 10% Owner
__X__ Officer (give title below) _____ Other (specify below)
Senior Vice President
5. If Amendment, Date Original Filed(Month/Day/Year)
(Street)

BALTIMORE, MD 21202
6. Individual or Joint/Group Filing(Check Applicable Line)
_X_ Form filed by One Reporting Person
___ Form filed by More than One Reporting Person
(City)
(State)
(Zip)
Table I - Non-Derivative Securities Beneficially Owned
1.Title of Security
(Instr. 4)
2. Amount of Securities Beneficially Owned
(Instr. 4)
3. Ownership Form: Direct (D) or Indirect (I)
(Instr. 5)
4. Nature of Indirect Beneficial Ownership
(Instr. 5)

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly. SEC 1473 (7-02)
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Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security
(Instr. 4)
2. Date Exercisable and Expiration Date
(Month/Day/Year)
3. Title and Amount of Securities Underlying Derivative Security
(Instr. 4)
4. Conversion or Exercise Price of Derivative Security 5. Ownership Form of Derivative Security: Direct (D) or Indirect (I)
(Instr. 5)
6. Nature of Indirect Beneficial Ownership
(Instr. 5)
Date Exercisable Expiration Date Title Amount or Number of Shares
Employee stock option (right to buy)   (1) 02/27/2019 Common Stock 14,420 $ 19.76 D  
Employee stock option (right to buy)   (2) 04/21/2018 Common Stock 3,200 $ 92.2 D  
Restricted stock units   (3)   (3) Common Stock 1,936.2644 (4) $ (5) D  

Reporting Owners

Reporting Owner Name / Address Relationships
Director 10% Owner Officer Other
Manasco Shon J.
100 CONSTELLATION WAY
BALTIMORE, MD 21202
      Senior Vice President  

Signatures

S J Manasco 08/20/2009
**Signature of Reporting Person Date

Explanation of Responses:

* If the form is filed by more than one reporting person, see Instruction 5(b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1) Option granted on 2/27/09 will vest in three equal annual installments on 2/27/10, 2/27/11, and 2/27/12.
(2) Option granted on 4/21/08 will vest in three equal annual installments beginning on 2/21/09. The second and third installments will vest on 2/21/10 and 2/21/11.
(3) Units granted on 4/21/08 will vest in three equal annual installments beginning on 4/21/09. The second and third installments will vest on 4/21/10 and 4/21/11.
(4) This amount is the remaining balance on units granted on 4/21/08 and includes shares obtained through reinvested dividends. The first installment vested on 4/21/09 and the net shares after shares were withheld to pay the taxes due were sold prior to the reporting person becoming an insider subject to Section 16.
(5) The units may be settled at the sole discretion of the issuer in cash or common stock. In addition, the units will pay dividends which will be reinvested.

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