UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, DC 20549
SCHEDULE 13G
Under the Securities Exchange Act of 1934
(Amendment No. )*
Northwest Pipe Company
________________________________________________________________________________
(Name of Issuer)
Common Stock
________________________________________________________________________________
(Title of Class of Securities)
667746101
________________________________________________________________________________
(CUSIP Number)
December 31, 2002
________________________________________________________________________________
(Date of Event Which Requires Filing of this Statement)
Check the appropriate box to designate the rule pursuant to which this
Schedule is filed:
[X] Rule 13d-1(b)
[_] Rule 13d-1(c)
[_] Rule 13d-1(d)
*The remainder of this cover page shall be filled out for a reporting person's
initial filing on this form with respect to the subject class of securities, and
for any subsequent amendment containing information which would alter the
disclosures provided in a prior cover page.
The information required in the remainder of this cover page shall not be deemed
to be "filed" for the purpose of Section 18 of the Securities Exchange Act of
1934 ("Act") or otherwise subject to the liabilities of that section of the Act
but shall be subject to all other provisions of the Act (however, see the
Notes).
Page 1 of 10 pages
CUSIP No.667746101 13G Page 2 of 10 Pages
________________________________________________________________________________
1. NAME OF REPORTING PERSON
S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON
Liberty Wanger Asset Management, L.P. 36-3820584
________________________________________________________________________________
2. CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
(a) [_]
(b) [_]
Not Applicable
________________________________________________________________________________
3. SEC USE ONLY
________________________________________________________________________________
4. CITIZENSHIP OR PLACE OF ORGANIZATION
Delaware
________________________________________________________________________________
NUMBER OF 5. SOLE VOTING POWER
SHARES
None
_________________________________________________________________
BENEFICIALLY 6. SHARED VOTING POWER
OWNED BY
395,000
_________________________________________________________________
EACH 7. SOLE DISPOSITIVE POWER
REPORTING
None
_________________________________________________________________
PERSON 8. SHARED DISPOSITIVE POWER
WITH
395,000
________________________________________________________________________________
9. AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
395,000
________________________________________________________________________________
10. CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*
[-]
Not Applicable
________________________________________________________________________________
11. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9
6.0%
________________________________________________________________________________
12. TYPE OF REPORTING PERSON*
IA
________________________________________________________________________________
CUSIP No.667746101 13G Page 3 of 10 Pages
________________________________________________________________________________
1. NAME OF REPORTING PERSON
S.S OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY)
WAM Acquisition GP, Inc.
________________________________________________________________________________
2. CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
(a) [_]
(b) [_]
Not Applicable
________________________________________________________________________________
3. SEC USE ONLY
________________________________________________________________________________
4. CITIZENSHIP OR PLACE OF ORGANIZATION
Delaware
________________________________________________________________________________
NUMBER OF 5. SOLE VOTING POWER
SHARES
None
_________________________________________________________________
BENEFICIALLY 6. SHARED VOTING POWER
OWNED BY
395,000
_________________________________________________________________
EACH 7. SOLE DISPOSITIVE POWER
REPORTING
None
_________________________________________________________________
PERSON 8. SHARED DISPOSITIVE POWER
WITH
395,000
________________________________________________________________________________
9. AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
395,000
________________________________________________________________________________
10. CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*
[-]
Not Applicable
________________________________________________________________________________
11. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9
6.0%
________________________________________________________________________________
12. TYPE OF REPORTING PERSON*
CO
________________________________________________________________________________
CUSIP No.667746101 13G Page 4 of 10 Pages
________________________________________________________________________________
1. NAME OF REPORTING PERSON
S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON
Liberty Acorn Trust
________________________________________________________________________________
2. CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
(a) [_]
(b) [_]
Not Applicable
________________________________________________________________________________
3. SEC USE ONLY
________________________________________________________________________________
4. CITIZENSHIP OR PLACE OF ORGANIZATION
Massachusetts
________________________________________________________________________________
NUMBER OF 5. SOLE VOTING POWER
SHARES
None
_________________________________________________________________
BENEFICIALLY 6. SHARED VOTING POWER
OWNED BY
395,000
_________________________________________________________________
EACH 7. SOLE DISPOSITIVE POWER
REPORTING
None
_________________________________________________________________
PERSON 8. SHARED DISPOSITIVE POWER
WITH
395,000
________________________________________________________________________________
9. AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
395,000
________________________________________________________________________________
10. CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*
[-]
Not Applicable
________________________________________________________________________________
11. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9
6.0%
________________________________________________________________________________
12. TYPE OF REPORTING PERSON*
IV
________________________________________________________________________________
Item 1(a) Name of Issuer:
Northwest Pipe Company
Item 1(b) Address of Issuer's Principal Executive Offices:
200 S. W. Market Street
Suite 1800
Portland, OR 97201
Item 2(a) Name of Person Filing:
Liberty Wanger Asset Management, L.P. ("WAM")
WAM Acquisition GP, Inc., the general partner of WAM
("WAM GP")
Liberty Acorn Trust ("Acorn")
Item 2(b) Address of Principal Business Office:
WAM, WAM GP and Acorn are all located at:
227 West Monroe Street, Suite 3000
Chicago, Illinois 60606
Item 2(c) Citizenship:
WAM is a Delaware limited partnership; WAM
GP is a Delaware corporation; and Acorn is a
Massachusetts business trust.
Item 2(d) Title of Class of Securities:
Common Stock
Item 2(e) CUSIP Number:
667746101
Item 3 Type of Person:
(d) Acorn is an Investment Company under section
8 of the Investment Company Act.
(e) WAM is an Investment Adviser registered under
section 203 of the Investment Advisers Act of
1940; WAM GP is the General Partner of the
Investment Adviser.
Page 5 of 10 pages
Item 4 Ownership (at December 31, 2002):
(a) Amount owned "beneficially" within the
meaning of rule 13d-3:
395,000
(b) Percent of class:
6.0 % (based on 6,550,878 shares outstanding
as of November 11, 2002).
(c) Number of shares as to which such person has:
(i) sole power to vote or to direct
the vote: none
(ii) shared power to vote or to
direct the vote: 395,000
(iii) sole power to dispose or to
direct the disposition of: none
(iv) shared power to dispose or to
direct disposition of: 395,000
Item 5 Ownership of Five Percent or Less of a Class:
Not Applicable
Item 6 Ownership of More than Five Percent on Behalf of Another
Person:
The shares reported herein have been
acquired on behalf of discretionary clients
of WAM, including Acorn. Persons other than
WAM and WAM GP are entitled to receive all
dividends from, and proceeds from the sale
of, those shares. Acorn is the only such
person known to be entitled to all dividends
from, and all proceeds from the sale of,
shares reported herein to the extent of more
than 5% of the class.
Item 7 Identification and Classification of the Subsidiary Which
Acquired the Security Being Reported on by the Parent Holding
Company:
Not Applicable
Item 8 Identification and Classification of Members of the Group:
Not Applicable
Item 9 Notice of Dissolution of Group:
Not Applicable
Page 6 of 10 Pages
Item 10 Certification:
By signing below I certify that, to the best
of my knowledge and belief, the securities referred
to above were acquired and are held in the ordinary
course of business and 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.
Page 7 of 10 Pages
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: February 12, 2003
The undersigned corporation, on the date above
written, agrees and consents to the joint filing on
its behalf of this Schedule 13G in connection with
its beneficial ownership of the security reported
herein.
WAM Acquisition GP, Inc.
for itself and as general partner of
LIBERTY WANGER ASSET MANAGEMENT, L.P.
By: /s/ Bruce H. Lauer
--------------------------------------
Bruce H. Lauer
Senior Vice President and
Secretary
The undersigned corporation, on the date above
written, agrees and consents to the joint filing on
its behalf of this Schedule 13G in connection with
its beneficial ownership of the security reported
herein.
LIBERTY ACORN TRUST
By: /s/ Bruce H. Lauer
--------------------------------------
Bruce H. Lauer
Vice President, Treasurer and
Secretary
Page 8 of 10 Pages
Exhibit Index
Exhibit 1 Joint Filing Agreement dated as of February 12, 2003 by and
among Liberty Wanger Asset Management, L.P., WAM Acquisition
GP, Inc. and Liberty Acorn Trust
Page 9 of 10 Pages