FOURTH SUPPLEMENT DATED MARCH 23, 1998
TO THIRD SUPPLEMENT DATED FEBRUARY 25, 1998,
SECOND SUPPLEMENT DATED JANUARY 21, 1998,
PROSPECTUS SUPPLEMENT DATED DECEMBER 19, 1997,
AND PROSPECTUS DATED NOVEMBER 26, 1997
COSTCO COMPANIES, INC.
The following table adds UBS Securities LLC ("UBS") to the list of Selling
Securityholders previously set forth in the Prospectus dated November 26, 1997
("Prospectus") and the Prospectus Supplements dated December 19, 1997 ("December
Supplement"), January 21, 1998 ("January Supplement"), and February 25, 1998
("February Supplement"). The table also sets forth information as to additional
securities that were acquired by Donaldson Lufkin & Jenrette Securities Corp.
("DLJ") and Merrill Lynch, Pierce, Fenner & Smith, Inc. ("Merrill Lynch") since
each was last named as a Selling Securityholder. The amount of securities that
may be offered for sale by UBS, DLJ and Merrill Lynch pursuant to the
Registration Statement of which the Prospectus, December Supplement, January
Supplement, February Supplement and this supplement form a part is set forth in
the table opposite their names. Amounts shown for DLJ and Merrill Lynch are not
adjusted for any sales that DLJ or Merrill Lynch may have made pursuant to the
Registration Statement. DLJ has provided, and will continue to provide,
financial advisory services to Costco Companies, Inc. (the "Company") for which
DLJ has received customary fees. Hamilton E. James, a Managing Director of DLJ,
is a member of the Board of Directors of the Company. Except as set forth for
DLJ, none of the Selling Securityholders listed below has had a material
relationship with the Company or any of its predecessors or affiliates within
the past three years.
<TABLE>
<CAPTION>
Shares of Common Stock
Face Amount of Notes Owned Owned Prior
Selling Securityholder Prior to Offering to Offering (1)
- ---------------------- -------------------------- ----------------------
<S> <C> <C>
Donaldson Lufkin & Jenrette Securities Corporation $79,670,000(2) 904,613(2)
Merrill Lynch, Pierce, Fenner & Smith, Inc. $64,339,000(2) 730,537(2)
UBS Securities LLC $9,500,000 107,867
- --------------------------
(1) Includes the Shares into which the Notes are convertible.
(2) Includes securities previously registered.
</TABLE>
The date of this Prospectus Supplement is March 23, 1998.
