FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN 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 * Reiner Andres   2. Issuer Name and Ticker or Trading Symbol PROS Holdings, Inc. [PRO] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) __X__ Director _____ 10% Owner __X__ Officer (give title below) _____ Other (specify below) President & CEO (Last) (First) (Middle) 3100 MAIN STREET, SUITE 900 3. Date of Earliest Transaction (Month/Day/Year) 05/10/2012 (Street) HOUSTON, TX 77002 4. If Amendment, Date Original Filed(Month/Day/Year) 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 Acquired, Disposed of, or Beneficially Owned

1.Title of Security (Instr. 3) 2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common Stock 05/10/2012   M   8,750 A $ 16.86 (1) 124,784 D   Common Stock 05/10/2012   F   3,190 D $ 16.86 (1) 121,594 D

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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)

1. Title of Derivative Security (Instr. 3)

2. Conversion or Exercise Price of Derivative Security

3. Transaction Date (Month/Day/Year)

3A. Deemed Execution Date, if any (Month/Day/Year)

4. Transaction Code (Instr. 8)

5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5)

6. Date Exercisable and Expiration Date (Month/Day/Year)

7. Title and Amount of Underlying Securities (Instr. 3 and 4)

8. Price of Derivative Security (Instr. 5)

9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)

10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4)

11. Nature of Indirect Beneficial Ownership (Instr. 4)

Code

V

(A)

(D)

Date Exercisable

Expiration Date

Title

Amount or Number of Shares

Restricted Stock Units

(2)

05/10/2012

M

8,750

(3)

(3)

Common Stock

8,750

$ 0

158,750 (4)

D

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
Reiner Andres 3100 MAIN STREET SUITE 900 HOUSTON, TX 77002	X		President & CEO

Signatures

J. Scott McClendon, Attorney-in-fact for Andres Reiner		05/14/2012
**Signature of Reporting Person		Date

Explanation of Responses:

*	If the form is filed by more than one reporting person, see Instruction 4(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)	Represents the price of PROS Holdings, Inc. common stock at the close of market on May 10, 2012.
(2)	Each restricted stock unit represents the contingent right to receive one share of PROS Holdings, Inc. common stock.
(3)	The original restricted stock unit grant was awarded on May 10, 2011 in the amount of 35,000 restricted stock units and vest annually, in equal installments, over a four year period commencing May 10, 2012.
(4)	Includes (i) 15,000 of unvested restricted stock which will vest in equal installments over the next three years on February 24th associated with the March 9, 2010 grant, (ii) 37,500 of unvested restricted stock which will vest in in equal installments over the next three years on the date of grant associated with the December 14, 2010 grant, (iii) 26,250 of unvested restricted stock which will vest in equal installments over the next three years on the date of grant associated with the May 10, 2011 grant and (iv) 80,000 of unvested restricted stock units which will vest in equal installments over the next four years on January 1st associated with a February 14, 2012 grant.

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