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 * ADVENT INTERNATIONAL LIMITED PARTNERSHIP   2. Issuer Name and Ticker or Trading Symbol ASPEN TECHNOLOGY INC /DE/ [AZPN] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director _____ 10% Owner _____ Officer (give title below) __X__ Other (specify below) Member of group > 10% (Last) (First) (Middle) C/O ADVENT INTERNATIONAL CORPORATION, 75 STATE STREET, 29TH FLOOR 3. Date of Earliest Transaction (Month/Day/Year) 05/17/2006 (Street) BOSTON, MA 02109 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 05/17/2006   C   2,944,400 A $ 3.33 2,944,400 I see footnote (1)

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
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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

Series D-1 Convertible Preferred Stock

$ 3.33 (2)

05/17/2006

C

29,444

(3)

(3)

common stock

2,944,400

$ 0

265,291

I

see footnote (1)

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
ADVENT INTERNATIONAL LIMITED PARTNERSHIP C/O ADVENT INTERNATIONAL CORPORATION 75 STATE STREET, 29TH FLOOR BOSTON, MA 02109				Member of group > 10%

Signatures

/s/ Jarlyth H. Gibson, Assistant Compliance Officer		05/18/2006
**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)	These securities are indirectly beneficially owned as a General Partner of the following entities: Advent Energy II Limited Partnership, Advent PGGM Global Limited Partnership, Digital Media & Communications III Limited Partnership, Digital Media & Communications III-A Limited Partnership, Digital Media & Communications III-B Limited Partnership, Digital Media & Communications III-C Limited Partnership, Digital Media & Communications III-D C.V., Digital Media & Communications III-E C.V., Global Private Equity III Limited Partnership and Global Private Equity IV Limited Partnership.
(2)	Each of the Series D-1 shares is convertible into a number of shares of common stock equal to its stated value of $333.00 per share (subject to adjustment) divided by the conversion price of $3.33 per share (subject to adjustment).
(3)	Shares may be converted into common stock at any time and on a perpetual basis.

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