OMB
APPROVAL
|
||
UNITED
STATES
SECURITIES
AND EXCHANGE
COMMISSION
Washington,
D.C. 20549
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OMB
Number:
3235-0145
Expires:
February 28, 2009
Estimated
average burden hours per
response.........................................10.4
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TETRA
TECH, INC.
|
Common
Stock, par value $.01 per
share
|
88162G103
|
December
31, 2007
|
CUSIP
No.
88162G103
|
13G
|
Page
2 of 10
Pages
|
1
|
NAMES
OF REPORTING PERSONS
I.R.S.
IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY)
Ziff
Asset Management,
L.P.
|
2
|
CHECK
THE APPROPRIATE BOX IF A
MEMBER OF A GROUP (SEE
INSTRUCTIONS)
(a)
o
(b) o
|
3
|
SEC
USE ONLY
|
4
|
CITIZENSHIP
OR PLACE OF ORGANIZATION
Delaware
|
NUMBER
OF
SHARES
|
5
|
SOLE
VOTING POWER
0
|
BENEFICIALLY
OWNED
BY
|
6
|
SHARED
VOTING POWER
3,551,874
|
EACH
REPORTING
|
7
|
SOLE
DISPOSITIVE POWER
0
|
PERSON
WITH
|
8
|
SHARED
DISPOSITIVE POWER
3,551,874
|
9
|
AGGREGATE
AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
3,551,874
|
10
|
CHECK
IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES (SEE
INSTRUCTIONS)
o
|
11
|
PERCENT
OF CLASS REPRESENTED BY AMOUNT IN ROW (9)
6.1%
|
12
|
TYPE
OF REPORTING PERSON (SEE INSTRUCTIONS)
PN
|
CUSIP
No.
88162G103
|
13G
|
Page
3 of 10
Pages
|
1
|
NAMES
OF REPORTING PERSONS
I.R.S.
IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY)
PBK
Holdings, Inc.
|
2
|
CHECK
THE APPROPRIATE BOX IF A
MEMBER OF A GROUP (SEE
INSTRUCTIONS)
(a)
o
(b) o
|
3
|
SEC
USE ONLY
|
4
|
CITIZENSHIP
OR PLACE OF ORGANIZATION
Delaware
|
NUMBER
OF
SHARES
|
5
|
SOLE
VOTING POWER
0
|
BENEFICIALLY
OWNED
BY
|
6
|
SHARED
VOTING POWER
3,941,120
|
EACH
REPORTING
|
7
|
SOLE
DISPOSITIVE POWER
0
|
PERSON
WITH
|
8
|
SHARED
DISPOSITIVE POWER
3,941,120
|
9
|
AGGREGATE
AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
3,941,120
|
10
|
CHECK
IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES (SEE
INSTRUCTIONS) o
|
11
|
PERCENT
OF CLASS REPRESENTED BY AMOUNT IN ROW (9)
6.7%
|
12
|
TYPE
OF REPORTING PERSON (SEE INSTRUCTIONS)
CO
|
CUSIP
No.
88162G103
|
13G
|
Page
4 of 10
Pages
|
1
|
NAMES
OF REPORTING PERSONS
I.R.S.
IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY)
Philip
B. Korsant
|
2
|
CHECK
THE APPROPRIATE BOX IF A
MEMBER OF A GROUP (SEE
INSTRUCTIONS)
(a)
o
(b) o
|
3
|
SEC
USE ONLY
|
4
|
CITIZENSHIP
OR PLACE OF ORGANIZATION
United
States of
America
|
NUMBER
OF
SHARES
|
5
|
SOLE
VOTING POWER
0
|
BENEFICIALLY
OWNED
BY
|
6
|
SHARED
VOTING POWER
3,941,120
|
EACH
REPORTING
|
7
|
SOLE
DISPOSITIVE POWER
0
|
PERSON
WITH
|
8
|
SHARED
DISPOSITIVE POWER
3,941,120
|
9
|
AGGREGATE
AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
3,941,120
|
10
|
CHECK
IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES (SEE
INSTRUCTIONS)
o
|
11
|
PERCENT
OF CLASS REPRESENTED BY AMOUNT IN ROW (9)
6.7%
|
12
|
TYPE
OF REPORTING PERSON (SEE INSTRUCTIONS)
IN
|
CUSIP
No.
88162G103
|
13G
|
Page
5 of 10
Pages
|
1
|
NAMES
OF REPORTING PERSONS
I.R.S.
IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY)
ZBI
Equities, L.L.C.
|
2
|
CHECK
THE APPROPRIATE BOX IF A
MEMBER OF A GROUP (SEE INSTRUCTIONS)
(a)
o
(b) o
|
3
|
SEC
USE ONLY
|
4
|
CITIZENSHIP
OR PLACE OF ORGANIZATION
Delaware
|
NUMBER
OF
SHARES
|
5
|
SOLE
VOTING POWER
0
|
BENEFICIALLY
OWNED
BY
|
6
|
SHARED
VOTING POWER
3,941,120
|
EACH
REPORTING
|
7
|
SOLE
DISPOSITIVE POWER
0
|
PERSON
WITH
|
8
|
SHARED
DISPOSITIVE POWER
3,941,120
|
9
|
AGGREGATE
AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
3,941,120
|
10
|
CHECK
IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES (SEE
INSTRUCTIONS)
o
|
11
|
PERCENT
OF CLASS REPRESENTED BY AMOUNT IN ROW (9)
6.7%
|
12
|
TYPE
OF REPORTING PERSON (SEE INSTRUCTIONS)
IA
|
(a)
|
Amount beneficially
owned:
|
(b)
|
Percent
of class:
|
(c)
|
Number
of shares as to which such person has:
|
|
(i)
|
Sole
power to vote or to direct the vote:
|
|
(ii)
|
Shared
power to vote or to direct the vote:
|
|
(iii)
|
Sole
power to dispose or to direct the disposition:
|
|
(iv)
|
Shared
power to dispose or to direct the disposition:
|
ZIFF
ASSET MANAGEMENT, L.P.
By: PBK
Holdings, Inc., its general partner
|
|||
By:
|
/s/
DAVID GRAY
|
||
Name:
|
David
Gray
|
||
Title:
|
Vice
President
|
PBK
HOLDINGS, INC.
|
|||
By:
|
/s/
DAVID GRAY
|
||
Name:
|
David
Gray
|
||
Title:
|
Vice
President
|
||
/s/
PHILIP B.
KORSANT
|
|||
Philip
B. Korsant
|
ZBI
EQUITIES, L.L.C.
By: PBK
Holdings, Inc., its sole member
|
|||
By:
|
/s/
DAVID GRAY
|
||
Name:
|
David
Gray
|
||
Title:
|
Vice
President
|
ZIFF
ASSET MANAGEMENT, L.P.
By: PBK
Holdings, Inc., its general partner
|
|||
By:
|
/s/
DAVID GRAY
|
||
Name:
|
David
Gray
|
||
Title:
|
Vice
President
|
PBK
HOLDINGS, INC.
|
|||
By:
|
/s/
DAVID GRAY
|
||
Name:
|
David
Gray
|
||
Title:
|
Vice
President
|
||
/s/
PHILIP
B.
KORSANT
|
|||
Philip
B. Korsant
|
ZBI
EQUITIES, L.L.C.
By: PBK
Holdings, Inc., its sole member
|
|||
By:
|
/s/
DAVID GRAY
|
||
Name:
|
David
Gray
|
||
Title:
|
Vice
President
|