X0202 3 2004-12-16 0 0001136655 ARBINET THEXCHANGE INC ARBX 0001245733 MATTHEW LORI C/O JP MORGAN PARTNERS 1221 AVENUE OF THE AMERICAS 40TH FLOOR NEW YORK NY 10021 1 0 0 0 Series C Cumulative Convertible Preferred Stock Common Stock 2950877 I See footnote Series D Convertible Preferred Stock Common Stock 76901 I See footnote Series D-1 Convertible Preferred Stock Common Stock 8011468 I See footnote Series E Convertible Preferred Stock Common Stock 8011468 I See footnote Series E-1 Convertible Preferred Stock Common Stock 4806921 I See footnote Automatically converts into common stock of the Issuer, reflecting all stock splits and other adjustments pursuant to the Issuer's Certificate of Incorporation, as amended, upon the closing of the Issuer's initial public offering of common stock. Not applicable. The amounts shown represent the beneficial ownership of the Issuer's securities beneficially owned by J.P. Morgan Partners (23A SBIC), L.P. ("JPM 23A SBIC"), a portion of which may be deemed attributable to the reporting person because the reporting person is a Principal of J.P. Morgan Partners, LLC, the investment advisor to JPM 23A SBIC and a limited partner of JPMP Master Fund Manager, L.P. ("MF Manager"), a limited partner of JPM 23A SBIC. The actual pro rata portion of such beneficial ownership that may be deemed attributable to the reporting person is not readily determinable because it is subject to several variables, including the internal rate of return and vesting within JPM 23A SBIC and within MF Manager. The reporting person disclaims beneficial ownership in the securities to the extent it exceeds his pecuniary interest therein. /s/ Matthew J. Lori 2004-12-16