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 *
  TA ASSOCIATES INC
2. Date of Event Requiring Statement (Month/Day/Year)
06/27/2007
3. Issuer Name and Ticker or Trading Symbol
PROS Holdings, Inc. [PRO]
(Last)
(First)
(Middle)
JOHN HANCOCK TOWER 200, CLARENDON ST., 56TH FLOOR
4. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
__X__ Director _____ 10% Owner
_____ Officer (give title below) __X__ Other (specify below)
See Remarks
5. If Amendment, Date Original Filed(Month/Day/Year)
(Street)

BOSTON, MA 02116
6. Individual or Joint/Group Filing(Check Applicable Line)
___ Form filed by One Reporting Person
_X_ 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)
Common Stock 7,350,720 (1) (2)
I
See Footnote (1) (2)

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

Reporting Owners

Reporting Owner Name / Address Relationships
Director 10% Owner Officer Other
TA ASSOCIATES INC
JOHN HANCOCK TOWER 200
CLARENDON ST., 56TH FLOOR
BOSTON, MA 02116
  X     See Remarks
ADVENT ATLANTIC & PACIFIC III LP
JOHN HANCOCK TOWER 200
CLARENDON ST., 56TH FLOOR
BOSTON, MA 02116
  X     13(d) Group
TA EXECUTIVES FUND LLC
JOHN HANCOCK TOWER 200
CLARENDON ST., 56TH FLOOR
BOSTON, MA 02116
  X     13(d) Group
TA INVESTORS LLC
JOHN HANCOCK TOWER 200
CLARENDON ST., 56TH FLOOR
BOSTON, MA 02116
  X     13(d) Group
TA ASSOCIATES AAP III PARTNERS
JOHN HANCOCK TOWER 200
CLARENDON ST., 56TH FLOOR
BOSTON, MA 02116
  X     13(d) Group
TA ASSOCIATES VIII LLC
JOHN HANCOCK TOWER 200
CLARENDON ST., 56TH FLOOR
BOSTON, MA 02116
  X     13(d) Group
TA ADVENT VIII LP
JOHN HANCOCK TOWER 200
CLARENDON ST., 56TH FLOOR
BOSTON, MA 02116
  X     13(d) Group

Signatures

TA Associates, Inc., By Thomas P. Alber, Chief Financial Officer 06/27/2007
**Signature of Reporting Person Date

Advent Atlantic and Pacific III, L.P., By TA Associates AAP III Partners, Its General Partner, By TA Associates, Inc., Its General Partner, By Thomas P. Alber, Chief Financial Officer 06/27/2007
**Signature of Reporting Person Date

TA Executives Fund LLC, By TA Associates, Inc., Its Manager, By Thomas P. Alber, Chief Financial Officer 06/27/2007
**Signature of Reporting Person Date

TA Investors LLC, By TA Associates, Inc., Its Manager, By Thomas P. Alber, Chief Financial Officer 06/27/2007
**Signature of Reporting Person Date

TA Associates AAP III Partners, By TA Associates, Inc., Its General Partner, By Thomas P. Alber, Chief Financial Officer 06/27/2007
**Signature of Reporting Person Date

TA Associates VIII LLC, By TA Associates, Inc., Its Manager, By Thomas P. Alber, Chief Financial Officer 06/27/2007
**Signature of Reporting Person Date

TA/Advent VIII, L.P., By TA Associates VIII LLC, Its General Partner, By TA Associates, Inc., Its Manager, By Thomas P. Alber, Chief Financial Officer 06/27/2007
**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) The shares are held as follows: (i) 5,995,309 shares held of record by TA/Advent VIII, L.P., (ii) 1,125,248 shares held of record by Advent Atlantic and Pacific III, L.P., (iii) 110,259 shares held of record by TA Executives Fund LLC, and (iv) 119,904 shares held of record by TA Investors LLC (such entities, collectively, the "TA Funds").
(2) TA Associates, Inc. is the manager of TA Associates VIII LLC, which is the general partner of TA/Advent VIII L.P. TA Associates, Inc. is also the general partner of TA Associates AAP III Partners, which is the general partner of Advent Atlantic and Pacific III, L.P. TA Associates, Inc. is also the manager of TA Executives Fund LLC and TA Investors LLC. Each of TA Associates, Inc., TA Associates VIII LLC and TA Associates AAP III Partners may be deemed to have a beneficial interest in shares held by the TA Funds. Each of TA Associates, Inc., TA Associates VIII LLC and TA Associates AAP III Partners disclaims beneficial ownership of such shares, except to the extent of its pecuniary interest in such shares which is subject to indeterminable future events.
 
Remarks:
The reporting persons are members of a 13(d) group owning more than 10% of the issuer's outstanding common stock.  The reporting persons have a representative on the issuer's board of directors.  Kurt R. Jaggers currently serves as the reporting persons' representative on the board of directors and, as such, the reporting persons are deemed directors of the issurer.

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