SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549


SCHEDULE 13G


Under the Securities Exchange Act of 1934
(Amendment No.________)*



Sipex Corporation
 (Name of Issuer)

Common Stock (Par Value $.01)
(Title of Class of Securities)

829909100
(CUSIP Number)

Check the following box if a fee is being paid with this statement [ ].
A fee is not required only if the filing person:(1)has a previous statement
on file reporting beneficial ownership of more than five percent of the class
of securities described in Item 1; and (2) has filed no amendment
subsequent there to reporting beneficial ownership of five percent or
less of such class.)(See Rule 13d-7.)

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).









(Continued on following pages)
Page 1 of 6 Pages


CUSIP No. 829909100	 					Page 2 of 6


1.	NAME OF REPORTING PERSON
S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON

Brown Investment Advisory & Trust Company ("BIATC"), its
wholly owned subsidiary, Brown Investment Advisory Incorporated ("BAI").
52-1811121

2. CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
(a) [ ]
(b) [x]


3. SEC USE ONLY

4. CITIZENSHIP OR PLACE OF ORGANIZATION

Brown Investment Advisory & Trust Company and Brown Advisory
Incorporated are Maryland corporations.

NUMBER OF 		5 SOLE VOTING POWER
SHARES			     	 BIATC     266112 shares
			      	 BAI	   602087 shares
					   868199 shares

BENEFICIALLY		6 SHARED VOTING POWER
OWNED BY 			 BIATC	        0 shares
				 BAI	        0 shares
					        0 shares


EACH REPORTING 		7 SOLE DISPOSITIVE POWER
PERSON WITH		         BIATC	   241562 shares
			         BAI       602087 shares
					   843649 shares

			8 SHARED DISPOSITIVE POWER
				 BIATC	    22050 shares
				 BAI	        0 shares
					    22050 shares

CUSIP No. 829909100   					Page 3 of 6

9. AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
                                BIATC       266112 shares
				BAI	    602087 shares
	                                    868199 shares

10. CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*	[   ]

11. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

             	 BIATC	        1.0%
		 BAI	 	2.1%
			        3.1%

12. TYPE OF REPORTING PERSON*

		BIATC - BK
		BAI - IA

*SEE INSTRUCTIONS BEFORE FILLING OUT

Item 1. (a) NAME OF ISSUER: 	Sipex Corporation

(b) Address of Issuer's Principal Executive Offices:
233 South Hillview Drive, Milpitas, CA  95053


Item 2. (a) 	NAME OF PERSON FILING:

Brown Investment Advisory & Trust Company ("BIATC"), its wholly
owned subsidiary, Brown Investment Advisory Incorporated ("BAI").

(b)	ADDRESS OF PRINCIPAL BUSINESS OFFICE:

901 South Bond Street, Suite 400
Baltimore, Maryland 21231

(c) CITIZENSHIP:

Brown Investment Advisory & Trust Company and Brown Advisory
Incorporated are Maryland corporations.


CUSIP No. 829909100		 				Page 4 of 6

(d)  TITLE OF CLASS OF SECURITIES:

Common Stock of ($.01 par) of Sipex Corporation
(e) CUSIP Number:
829909100

Item 3. 	If this statement is filed pursuant to Rules 13d-1(b),
or 13d-2(b), check whether the person filing is a:

For BIATC

(b) [x] Bank as defined in section 3(a)(6) of the Act

For BAI

(e) [x] Investment Adviser registered under section 203 of the
Investment Advisers Act of 1940

Item 4. 	OWNERSHIP:

(a) AMOUNT BENEFICIALLY OWNED:		As of April 30, 2003

                BIATC	           266112 shares
		BAI	           602087 shares
				   868199 shares

(b) PERCENT OF CLASS:

   		BIATC		1.0%
		BAI	 	2.1%
			        3.1%

(c) Number of shares as to which such person has:

(i)	sole power to vote or to direct the vote:

 			BIATC	      266112 shares
			BAI	      602087 shares
			              868199 shares



CUSIP No. 829909100   					Page 5 of 6

(ii) shared power to vote or to direct the vote:

			BIATC	            0 shares
			BAI		    0 shares
				            0 shares

(iii) sole power to dispose or to direct the disposition of:

			BIATC	       241562 shares
			BAI	       602087 shares
				       843649 shares

(iv) shared power to dispose or to direct the disposition of:

			BIATC	    	22050 shares
			BAI		    0 shares
					22050 shares

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.

		Not applicable

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


CUSIP No. 829909100		 				Page 6 of 6

Item 10. CERTIFICATION.


By signing below I certify that to the best of my knowledge and
belief, the securities referred to above were acquired in the
ordinary course of business and were not acquired for the purpose
of and do not have the effect of changing or influencing the
control of the issuer of such securities and were not acquired in
connection with or as a participant in any transaction having such
purpose or effect.


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:	As of April 30, 2003

Signature:	Brown Investment Advisory & Trust Company

	By: /S/ Sandra J. Doeller

Title:	Principal

Signature:	Brown Investment Advisory Incorporated

	By: /S/ Sandra J. Doeller


	Title:	Principal