CUSIP No. 045327103
1. NAME OF REPORTING PERSON
S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON
1818 MASTER PARTNERS, LTD.
Tax ID. 98-0335961
2. CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
(a) [ ]
(b) [ ]
3. SEC USE ONLY
4. CITIZENSHIP OR PLACE OF ORGANIZATION
CAYMAN
5. SOLE VOTING POWER
0
6. SHARED VOTING POWER
3,677,229
7. SOLE DISPOSITIVE POWER
0
8. SHARED DISPOSITIVE POWER
3,677,229
9. AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
3,677,229
10. CHECK BOX IF THE AGGREGATE AMOUNT IN ROW(9) EXCLUDES CERTAIN
SHARES* [ ]
11. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW [9]
3.95%
12. TYPE OF REPORTING PERSON*
CO
1. NAME OF REPORTING PERSON
S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON
RICHARD H. WITMER
2. CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
(a) [ ]
(b) [ ]
3. SEC USE ONLY
4. CITIZENSHIP OR PLACE OF ORGANIZATION
US CITIZEN
5. SOLE VOTING POWER
0
6. SHARED VOTING POWER
3,677,229
7. SOLE DISPOSITIVE POWER
0
8. SHARED DISPOSITIVE POWER
3,677,229
9. AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
3,677,229
10. CHECK BOX IF THE AGGREGATE AMOUNT IN ROW(9) EXCLUDES CERTAIN
SHARES* [ ]
11. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW [9]
3.95%
12. TYPE OF REPORTING PERSON*
IN
1. NAME OF REPORTING PERSON
S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON
TIMOTHY E. HARTCH
2. CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
(a) [ ]
(b) [ ]
3. SEC USE ONLY
4. CITIZENSHIP OR PLACE OF ORGANIZATION
US CITIZEN
5. SOLE VOTING POWER
0
6. SHARED VOTING POWER
3,677,229
7. SOLE DISPOSITIVE POWER
0
8. SHARED DISPOSITIVE POWER
3,677,229
9. AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
3,677,229
10. CHECK BOX IF THE AGGREGATE AMOUNT IN ROW(9) EXCLUDES CERTAIN
SHARES* [ ]
11. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW [9]
3.95%
12. TYPE OF REPORTING PERSON*
IN
1. NAME OF REPORTING PERSON
S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON
BROWN BROTHERS HARRIMAN & CO.
13-4973745
2. CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
(a) [ ]
(b) [ ]
3. SEC USE ONLY
4. CITIZENSHIP OR PLACE OF ORGANIZATION
NEW YORK
5. SOLE VOTING POWER
0
6. SHARED VOTING POWER
5,128,373
7. SOLE DISPOSITIVE POWER
0
8. SHARED DISPOSITIVE POWER
3,677,229
9. AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
3,677,229
10. CHECK BOX IF THE AGGREGATE AMOUNT IN ROW(9) EXCLUDES
CERTAIN SHARES* [ ]
11. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW [9]
3.95%
12. TYPE OF REPORTING PERSON*
HC
Item 1 (a). Name of Issuer:
Aspen Technology, Inc.
Item 1 (b). Address of issuer's principal executive offices:
200 Wheeler Road
Burlington, MA 02141
Item 2 (a). Name of persons filing:
Brown Brothers Harriman & Co.
on behalf of itself and:
1818 Master Partners, Ltd.
Richard H. Witmer
Timothy E. Hartch
Item 2(b). Address of principal business office:
140 Broadway
New York City, NY 10005
Item 2(c). Citizenship/Place of Organization:
Brown Brothers Harriman & Co., New York
1818 Master Partners, Ltd., Cayman
Richard H. Witmer, United States Citizen
Timothy E. Hartch, United States Citizen
Item 2(d). Title of class of securities:
COMMON (the "Shares")
Item 2(e). CUSIP Number:
045327103
Item 3. If this statement is filed pursuant to Rules 13d-1(b)
or 13d-2(b) or (c), check whether the person filing is a:
Not applicable.
Item 4. Ownership:
With respect to the beneficial ownership of the reporting persons,
see Items 5 through 11 of the respective cover pages to this
Schedule 13G, which are incorporated herein by reference.
By virtue of a resolution adopted by Brown Brothers Harriman & Co.
("BBH&Co.") on May 6, 2003, designating Richard H. Witmer and
Timothy E. Hartch, or either of them, as the sole and exclusive
persons at BBH&Co. having voting power (including the power to
vote or to direct the vote) and investment power (including the
power to dispose or to direct the disposition) with respect to all
investments of 1818 Master Partners, Ltd., each of Mssrs. Witmer
and Hartch may be deemed to beneficially own 3,677,229 shares,
pursuant to Rule 13d-3 of the Act.
Item 5. Ownership of 5 Percent or Less of a Class
Not applicable.
Item 6. Ownership of More than 5 Percent on Behalf of Another Person
The Shares are held by 1818 Master Partners, Ltd. on behalf of
investors in 1818 Partners, L.P. To the best of the
undersigned's knowledge and belief, no other person has such
an economic interest relating to more than 3.95% of the class of
reported shares.
Item 7. Identification and Classification of the Subsidiary
Which Acquired the Security Being Reported on By the Parent
Holding Company or Control Person
The securities being reported are beneficially owned by
1818 Master Partners, Ltd., of which Brown Brothers Harriman & Co
is a control person based upon its holding of all the voting interests
in, and directing the management of, 1818 Master Partners, Ltd.
A copy of the Agreement by and among Brown Brothers Harriman & Co.,
1818 Master Partners, Ltd., Richard H. Witmer and Timothy E. Hartch
authorizing the filing of one Schedule 13G on behalf of each entity
or individual is set forth below:
Agreement
The undersigned hereby agree to file jointly the attached statement or
amendment on Schedule 13G and any further amendments thereto pursuant
to Regulation 13G promulgated by the Securities and Exchange Commission
under the Securities Exchange Act of 1934. Such filing shall be made
by Brown Brothers Harriman & Co. on its behalf and on behalf of the other
parties hereto.
Date: 9/30/10
BROWN BROTHERS HARRIMAN & CO.
By: /s/ Gregory Russell
_______________________________
Name: Gregory Russell
Title: Associate
1818 MASTER PARTNERS, LTD.
By: /s/ Richard H. Witmer
_______________________________
Name: Richard H. Witmer
Title: Director
RICHARD H. WITMER
By: /s/ Richard H. Witmer
_______________________________
Name: Richard H. Witmer, as Partner, Brown Brothers
Harriman & Co., and in individual capacity.
TIMOTHY E. HARTCH
By: /s/ Timothy E. Hartch
_______________________________
Name: Timothy E. Hartch, as Partner, Brown Brothers
Harriman & Co., and in individual capacity.
Item 8. Identification and Classification of Members of the Group
Not applicable.
Item 9. Notice of Dissolution of Group
Not applicable.
Item 10. Certification
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 that purpose or effect.
Disclaimer of Beneficial Ownership
The undersigned expressly declare that the filing of this Schedule
shall not be construed as an admission that the undersigned are, for
purpose of Sections 13(d) and 13(g) of the Securities Exchange Act of
1934, the beneficial owners of any securities covered by this Schedule
13G.
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.
Date: 9/30/10
BROWN BROTHERS HARRIMAN & CO.
By: /s/ Gregory Russell
_______________________________
Name: Gregory Russell
Title: Associate
1818 MASTER PARTNERS, LTD.
By: /s/ Richard H. Witmer
_______________________________
Name: Richard H. Witmer
Title: Director
RICHARD H. WITMER
By: /s/ Richard H. Witmer
_______________________________
Name: Richard H. Witmer, as Partner, Brown Brothers
Harriman & Co., and in individual capacity.
TIMOTHY E. HARTCH
By: /s/ Timothy E. Hartch
_______________________________
Name: Timothy E. Hartch, as Partner, Brown Brothers
Harriman & Co., and in individual capacity.