As filed with the Securities and Exchange Commission on May 11, 2001.

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

FORM 8-A

For Registration of Certain Classes of Securities
Pursuant to Section 12(b) or 12(g) of the
Securities Exchange Act of 1934

Tellium, Inc.
(Exact name of registrant as specified in its charter) 

           Delaware                                           22-3509099
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(State of incorporation or organization)                   (I.R.S. Employer
                                                           Identification No.)

2 Crescent Place, Oceanport, New Jersey                        07757-0901
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(Address of principal executive offices)                       (Zip Code)

If this Form relates to the registration of a class of securities pursuant to
Section 12(b) of the Exchange Act and is effective pursuant to General Instruction A.(c), check the following box. [_]

If this Form relates to the registration of a class of securities pursuant to
Section 12(g) of the Exchange Act and is effective pursuant to General Instruction A.(d), check the following box. [X]

Securities Act registration statement file number to which this form relates:
333-46362.

Securities to be registered pursuant to Section 12(b) of the Act: 

Title of each class                       Name of each exchange on
to be so registered             which each class is to be registered
-------------------             ------------------------------------
       None                                         None

Securities to be registered pursuant to Section 12(g) of the Act:

Common Stock, $0.001 par value per share
(Title of class)

INFORMATION REQUIRED IN REGISTRATION STATEMENT

Item 1. Description of the Registrant's Securities to be Registered

The description of the common stock, $0.001 par value per share, of Tellium, Inc. (the "Registrant") to be registered hereunder is contained under the caption "Description of Capital Stock" in the Prospectus constituting a part of the Registration Statement on Form S-1 (No. 333-46362) filed by the Registrant with the Securities and Exchange Commission on September 22, 2000, as amended, which is incorporated herein by reference as Exhibit 1.

Item 2. Exhibits

The following exhibits to this Registration Statement have been filed as exhibits to the Registration Statement on Form S-1 (No. 333-46362) and are hereby incorporated herein by reference:

1. Registration Statement on Form S-1 (No. 333-46362) filed on September 22, 2000, as amended.

2. Form of Restated Certificate of Incorporation of the Registrant (Exhibit 3.1 to the Registration Statement on Form S-1 (No. 333- 46362)).

3. Form of Amended and Restated Bylaws of the Registrant (Exhibit 3.2 to the Registration Statement on Form S-1 (No. 333-46362)).

4. Form of certificate of common stock of the Registrant, $0.001 par value (Exhibit 4.1 to the Registration Statement on Form S-1 (No. 333- 46362)).

SIGNATURE

Pursuant to the requirements of Section 12 of the Securities Exchange Act of 1934, as amended, the Registrant has duly caused this Registration Statement to be signed on its behalf by the undersigned, thereto duly authorized.

Date: May 11, 2001

TELLIUM, INC. 

By:  /s/ Harry J. Carr
     -----------------
         Harry J. Carr
         Chief Executive Officer