SEC Form 3

FORM 3

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person* Rosenbaum Robert B (Last) (First) (Middle) C/O WESCO INTERNATIONAL INC. 225 WEST STATION SQUARE DRIVE (Street) PITTSBURGH PA 15219 (City) (State) (Zip)	2. Date of Event Requiring Statement (Month/Day/Year) 05/11/1999	3. Issuer Name and Ticker or Trading Symbol WESCO INTERNATIONAL INC [ WCC ]
		4. Relationship of Reporting Person(s) to Issuer (Check all applicable) Director 10% Owner X Officer (give title below) Other (specify below) Vice President, Operations	5. If Amendment, Date of Original Filed (Month/Day/Year) 05/11/1999
			6. Individual or Joint/Group Filing (Check Applicable Line) X Form filed by One Reporting Person Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Beneficially Owned
1. Title of Security (Instr. 4)	2. Amount of Securities Beneficially Owned (Instr. 4)	3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	4. Nature of Indirect Beneficial Ownership (Instr. 5)
Common Stock, par value $.01 per share	144,500	D

Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 4)	2. Date Exercisable and Expiration Date (Month/Day/Year)		3. Title and Amount of Securities Underlying Derivative Security (Instr. 4)		4. Conversion or Exercise Price of Derivative Security	5. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
$30,000,000 Convertible Promissory Note due March 31, 2000(1)	05/11/1999(2)	05/11/1999(2)	Common Stock	1,610,916	(3)	I	see footnote 1(1)

Explanation of Responses:

1. As co-trustee of (i) the Robert B. Rosenbaum Trust, (ii) the Marlon R. Rosenbaum Trust, and (iii) the Jessica Rosenbaum Trust, for all of which the reporting person's immediate family members are either the direct or remote beneficiaries. These three trusts are the sole owners of Bruckner Supply Company, Inc., the direct owner of the $30,000,000 Convertible Promissory Note and the shares issuable upon conversion of such note.

2. The entire promissory note was by its terms automatically converted into shares of common stock on the closing date of the initial public offering of WESCO International, Inc.

3. The promissory note was convertible into such number of shares of common stock as was derived by dividing the principal amount of the promissory note by the initial public offering price per share of common stock of WESCO International, Inc.

	/s/Robert B. Rosenbaum	10/05/2004
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 5 (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).
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