------------------- ------------------ CUSIP No. 532226107 Page 1 of 15 Pages ------------------- ------------------ SEC 1745 (02-02): Potential persons who are to respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB control number. OMB APPROVAL OMB Number: 3235-0145 Expires: December 31, 2005 Estimated average burden hours per response. . . 11 UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 ----------------------------------------- (Amendment No. 2) Lightbridge, Inc. ----------------- (Name of Issuer) Common Stock ------------------------------ (Title of Class of Securities) 532226107 -------------- (CUSIP Number) December 31, 2005 ------------------------------------------------------- (Date of Event which Requires Filing of this Statement) Check the appropriate box to designate the rule pursuant to which this Schedule is filed: [x] Rule 13d-1(b) [ ] Rule 13d-1(c) [ ] Rule 13d-1(d) 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. Page 1 of 15 Pages ------------------- ------------------ CUSIP No. 532226107 Page 2 of 15 Pages ------------------- ------------------ ------------------------------------------------------------------------ NAME OF REPORTING PERSON 1 SS. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON Sidus Investment Partners, L.P. Tax I.D.#:13-4100882 ------------------------------------------------------------------------ CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (a) [x] 2 (b) [ ] ------------------------------------------------------------------------ SEC USE ONLY 3 ------------------------------------------------------------------------ CITIZENSHIP OR PLACE OF ORGANIZATION 4 DELAWARE ------------------------------------------------------------------------ SOLE VOTING POWER 5 0 NUMBER OF SHARES BENEFICIALLY OWNED BY ------------------------------------------------- EACH REPORTING PERSON WITH 6 SHARED VOTING POWER 1,136,650 ------------------------------------------------ SOLE DISPOSITIVE POWER 7 0 ------------------------------------------------ SHARED DISPOSITIVE POWER 8 1,136,650 ------------------------------------------------------------------------ 9 AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 4.3% ------------------------------------------------------------------------ 10 CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES [ ] ------------------------------------------------------------------------ 11 PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9) 4.3% ------------------------------------------------------------------------ 12 TYPE OF REPORTING PERSON PN ------------------------------------------------------------------------ ------------------- ------------------ CUSIP No. 532226107 Page 3 of 15 Pages ------------------- ------------------ ------------------------------------------------------------------------ NAME OF REPORTING PERSON 1 SS. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON Sidus Investment Ltd. ------------------------------------------------------------------------ CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (a) [x] 2 (b) [ ] ------------------------------------------------------------------------ SEC USE ONLY 3 ------------------------------------------------------------------------ CITIZENSHIP OR PLACE OF ORGANIZATION 4 CAYMAN ISLANDS ------------------------------------------------------------------------ SOLE VOTING POWER 5 0 NUMBER OF SHARES BENEFICIALLY OWNED BY ------------------------------------------------- EACH REPORTING PERSON WITH 6 SHARED VOTING POWER 1,136,650 ------------------------------------------------ SOLE DISPOSITIVE POWER 7 0 ------------------------------------------------ SHARED DISPOSITIVE POWER 8 1,136,650 ------------------------------------------------------------------------ 9 AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 4.3% ------------------------------------------------------------------------ 10 CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES [ ] ------------------------------------------------------------------------ 11 PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9) 4.3% ------------------------------------------------------------------------ 12 TYPE OF REPORTING PERSON OO ------------------------------------------------------------------------ ------------------- ------------------ CUSIP No. 532226107 Page 4 of 15 Pages ------------------- ------------------ ------------------------------------------------------------------------ NAME OF REPORTING PERSON 1 SS. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON Sidus Investment Management, LLC (1) 13-4099498 ------------------------------------------------------------------------ CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (a) [x] 2 (b) [ ] ------------------------------------------------------------------------ SEC USE ONLY 3 ------------------------------------------------------------------------ CITIZENSHIP OR PLACE OF ORGANIZATION 4 DELAWARE ------------------------------------------------------------------------ SOLE VOTING POWER 5 0 NUMBER OF SHARES BENEFICIALLY OWNED BY ------------------------------------------------- EACH REPORTING PERSON WITH 6 SHARED VOTING POWER 1,136,650 ------------------------------------------------ SOLE DISPOSITIVE POWER 7 0 ------------------------------------------------ SHARED DISPOSITIVE POWER 8 1,136,650 ------------------------------------------------------------------------ 9 AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 4.3% ------------------------------------------------------------------------ 10 CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES [ ] ------------------------------------------------------------------------ 11 PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9) 4.3% ------------------------------------------------------------------------ 12 TYPE OF REPORTING PERSON IA ------------------------------------------------------------------------ ------------------- 1 Sidus Investment Management, LLC beneficially owns less than 5% of the Common Stock of Lightbridge, Inc. for the benefit of a managed account advised by Sidus Investment Management, LLC. ------------------- ------------------ CUSIP No. 532226107 Page 5 of 15 Pages ------------------- ------------------ ------------------------------------------------------------------------ NAME OF REPORTING PERSON 1 SS. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON Alfred V. Tobia, Jr. ------------------------------------------------------------------------ CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (a) [x] 2 (b) [ ] ------------------------------------------------------------------------ SEC USE ONLY 3 ------------------------------------------------------------------------ CITIZENSHIP OR PLACE OF ORGANIZATION 4 UNITED STATES ------------------------------------------------------------------------ SOLE VOTING POWER 5 0 NUMBER OF SHARES BENEFICIALLY OWNED BY ------------------------------------------------- EACH REPORTING PERSON WITH 6 SHARED VOTING POWER 1,136,650 ------------------------------------------------ SOLE DISPOSITIVE POWER 7 0 ------------------------------------------------ SHARED DISPOSITIVE POWER 8 1,136,650 ------------------------------------------------------------------------ 9 AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 4.3% ------------------------------------------------------------------------ 10 CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES [ ] ------------------------------------------------------------------------ 11 PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9) 4.3% ------------------------------------------------------------------------ 12 TYPE OF REPORTING PERSON IN ------------------------------------------------------------------------ ------------------- ------------------ CUSIP No. 532226107 Page 6 of 15 Pages ------------------- ------------------ --------- -------------------------------------------------------------- NAME OF REPORTING PERSON 1 SS. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON Michael J. Barone --------- -------------------------------------------------------------- CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (a) [x] 2 (b) [ ] --------- -------------------------------------------------------------- SEC USE ONLY 3 --------- -------------------------------------------------------------- CITIZENSHIP OR PLACE OF ORGANIZATION 4 UNITED STATES ----------------------- ------------------------------------------------ SOLE VOTING POWER 5 0 NUMBER OF SHARES BENEFICIALLY OWNED BY ------------------------------------------------- EACH REPORTING PERSON WITH 6 SHARED VOTING POWER 1,136,650 ------------------------------------------------ SOLE DISPOSITIVE POWER 7 0 ------------------------------------------------ SHARED DISPOSITIVE POWER 8 1,136,650 ------------------------------------------------------------------------ 9 AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 4.3% ------------------------------------------------------------------------ 10 CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES [ ] ------------------------------------------------------------------------ 11 PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9) 4.3% ------------------------------------------------------------------------ 12 TYPE OF REPORTING PERSON IN ------------------------------------------------------------------------ ------------------- ------------------ CUSIP No. 532226107 Page 7 of 15 Pages ------------------- ------------------ ITEM 1. (a). Name of Issuer: LIGHTBRIDGE, INC. (b). Address of Issuer's Principal Executive Offices: 30 Corporate Drive Burlington, Massachusetts 01803 ITEM 2. (a). Name of Persons Filing: This Statement is being filed jointly by (i) Sidus Investment Partners, L.P., a Delaware limited partnership ("Sidus Partners"); (ii) Sidus Investments Ltd., a Cayman Islands exempted corporation, ("Sidus Investments"); (iii) Sidus Investment Management, LLC, a Delaware limited liability company, which serves as investment manager to Sidus Partners, Sidus Investments, and a certain managed account which is a beneficial owner of shares (the "Manager"); (iv) Messrs. Alfred V. Tobia, Jr. and Michael J. Barone, who serves as the managing members of the Manager. Sidus Partners, Sidus Investments, the Manager, and Messrs. Tobia and Barone are sometimes also referred to herein individually as a "Reporting Person" and collectively as "Reporting Persons". (b). Address of Principal Business Office for Each of the Above: (i) Sidus Investment Partners, L.P. -- The address of Sidus Partners' principal business office is 767 Third Avenue, 15th Floor, New York, New York, 10017. (ii) Sidus Investments, Ltd. -- The address of Sidus Investments' principal business office is 767 Third Avenue, 15th Floor, New York, New York, 10017. (iii) Sidus Investment Management, LLC -- The address of the Manager's principal business office is 767 Third Avenue, 15th Floor, New York, New York, 10017. (iv) Alfred V. Tobia, Jr. -- Mr. Alfred V. Tobia, Jr.'s principal business office is 767 Third Avenue, 15th Floor, New York, New York, 10017. (v) Michael J. Barone -- Mr. Michael J. Barone's principal business office is 767 Third Avenue, 15th Floor, New York, New York, 10017 (c). Citizenship or Place of Organization: Sidus Partners and the Manager are organized under the laws of the State of Delaware. Sidus Investments is an exempted company incorporated under the laws of the Cayman Islands. Messrs. Tobia and Barone are citizens of the United States. ------------------- ------------------ CUSIP No. 532226107 Page 8 of 15 Pages ------------------- ------------------ (d). Title of Class of Securities: Common Stock (e). CUSIP Number: 53222617 ITEM 3. If this Statement is Filed Pursuant to Rules 13d-1(b) or 13d-2(b) or (c), Check Whether the Person Filing is a: (a) [ ] Broker or dealer registered under Section 15 of the Exchange Act; (b) [ ] Bank as defined in Section 3(a)(6) of the Exchange Act; (c) [ ] Insurance company as defined in Section 3(a)(19) of the Exchange Act; (d) [ ] Investment company registered under Section 8 of the Investment Company Act; (e) [X] An investment adviser in accordance with Rule 13d-1(b)(1)(ii)(E); (f) [ ] An employee benefit plan or endowment fund in accordance with Rule 13d-1(b)(1)(ii)(F); (g) [ ] A parent holding company or control person in accordance with Rule 13d-1(b)(1)(ii)(G); (h) [ ] A savings associations as defined in Section 3(b) of the Federal Deposit Insurance Act; (i) [ ] A church plan that is excluded from the definition of an investment company under Section 3(c)(14) of the Investment Company Act of 1940; (j) [ ] Group, in accordance with Rule 13d-1(b)(1)(ii)(J). ITEM 4. Ownership. (a). Amount beneficially owned: (i) Sidus Investment Partners, L.P. 1,136,650 (ii) Sidus Investments, Ltd. 1,136,650 (iii) Sidus Investment Management, LLC(2) 1,136,650 (iv) Alfred V. Tobia, Jr.(3) 1,136,650 ---------------- 2 Sidus Investment Management, LLC is the investment manager of Sidus Investment Partners, L.P. and Sidus Investments, Ltd., subject to the overall control of the managing members, Alfred V. Tobia, Jr. and Michael J. Barone, and thus could be deemed to share the power to vote and dispose or direct the disposition of such Shares. 3 Alfred V. Tobia, Jr. is a managing member of Sidus Investment Management, LLC, and thus could be deemed to share the power to vote and dispose or direct the disposition of such Shares. ------------------- ------------------ CUSIP No. 532226107 Page 9 of 15 Pages ------------------- ------------------ (v) Michael J. Barone(4) 1,136,650 (b). Percentage of class: (i) Sidus Investment Partners, L.P. 4.3% (ii) Sidus Investments, Ltd. 4.3% (iii) Sidus Investment Management, LLC(5) 4.3% (iv) Alfred V. Tobia, Jr.(6) 4.3% (v) Michael J. Barone(7) 4.3% (c). Number of shares as to which such person has: (1) Sole power to vote or to direct the vote: (i) Sidus Investment Partners, L.P. 0 (ii) Sidus Investments, Ltd. 0 (iii) Sidus Investment Management, LLC(8) 0 (iv) Alfred V. Tobia, Jr.(9) 0 ---------------- 4 Michael J. Barone is a managing member of Sidus Investment Management, LLC, and thus could be deemed to share the power to vote and dispose or direct the disposition of such Shares. 5 Sidus Investment Management, LLC is the investment manager of Sidus Investment Partners, L.P. and Sidus Investments, Ltd., subject to the overall control of the managing members, Alfred V. Tobia, Jr. and Michael J. Barone, and thus could be deemed to share the power to vote and dispose or direct the disposition of such Shares. 6 Alfred V. Tobia, Jr. is a managing member of Sidus Investment Management, LLC, and thus could be deemed to share the power to vote and dispose or direct the disposition of such Shares. 7 Michael J. Barone is a managing member of Sidus Investment Management, LLC, and thus could be deemed to share the power to vote and dispose or direct the disposition of such Shares. 8 Sidus Investment Management, LLC is the investment manager of Sidus Investment Partners, L.P. and Sidus Investments, Ltd., subject to the overall control of the managing members, Alfred V. Tobia, Jr. and Michael J. Barone, and thus could be deemed to share the power to vote and dispose or direct the disposition of such Shares. ------------------- ------------------- CUSIP No. 532226107 Page 10 of 15 Pages ------------------- ------------------- (v) Michael J. Barone(10) 0 (2) Shared power to vote or to direct the vote: (i) Sidus Investment Partners, L.P. 1,136,650 (ii) Sidus Investments, Ltd. 1,136,650 (iii) Sidus Investment Management, LLC 1,136,650 (iv) Alfred V. Tobia, Jr. 1,136,650 (v) Michael J. Barone 1,136,650 (3) Sole power to dispose or to direct the disposition of: (i) Sidus Investment Partners, L.P. 0 (ii) Sidus Investments, Ltd. 0 (iii) Sidus Investment Management, LLC(11) 0 (iv) Alfred V. Tobia, Jr.(12) 0 (v) Michael J. Barone(13) 0 ---------------- 9 Alfred V. Tobia, Jr. is a managing member of Sidus Investment Management, LLC, and thus could be deemed to share the power to vote and dispose or direct the disposition of such Shares. 10 Michael J. Barone is a managing member of Sidus Investment Management, LLC, and thus could be deemed to share the power to vote and dispose or direct the disposition of such Shares. 11 Sidus Investment Management, LLC is the investment manager of Sidus Investment Partners, L.P. and Sidus Investments, Ltd., subject to the overall control of the managing members, Alfred V. Tobia, Jr. and Michael J. Barone, and thus could be deemed to share the power to vote and dispose or direct the disposition of such Shares. 12 Alfred V. Tobia, Jr. is a managing member of Sidus Investment Management, LLC, and thus could be deemed to share the power to vote and dispose or direct the disposition of such Shares. 13 Michael J. Barone is a managing member of Sidus Investment Management, LLC, and thus could be deemed to share the power to vote and dispose or direct the disposition of such Shares. ------------------- ------------------- CUSIP No. 532226107 Page 11 of 15 Pages ------------------- ------------------- (4) Shared power to dispose or to direct the disposition of: (i) Sidus Investment Partners, L.P. 1,136,650 (ii) Sidus Investments, Ltd. 1,136,650 (iii) Sidus Investment Management, LLC 1,136,650 (iv) Alfred V. Tobia, Jr. 1,136,650 (v) Michael J. Barone 1,136,650 ITEM 5. Ownership of Five Percent or Less of a Class: If this statement is being filed to report the fact that as of the date hereof the reporting person has ceased to be the beneficial owner of more than five percent of the class of securities, check the following: [x] ITEM 6. Ownership of More than Five Percent on Behalf of Another Person: The Shares owned by Sidus Partners, Sidus Investments, the Manager, and Messrs. Alfred V. Tobia, Jr. and Michael J. Barone are beneficially owned by Sidus Partners, Sidus Investments, and the Manager (on behalf of a certain managed account advised by the Manager). Sidus Partners, Sidus Investments, the Manager, and Messrs. Alfred V. Tobia, Jr. and Michael J. Barone individually beneficially own less than 5% of the Shares. Each of Sidus Partners, Sidus Investments, the Manager, and Messrs. Alfred V. Tobia, Jr. and Michael J. Barone may be deemed to possess the power to vote and dispose or direct the disposition of the Shares. ITEM 7. Identification and Classification of Subsidiaries which Acquired the Security Being Reported on by the Parent Holding Company: Not Applicable. ITEM 8. Identification and Classification of Members of the Group: See Item 2. ITEM 9. Notice of Dissolution of Group: Not Applicable. ------------------- ------------------- CUSIP No. 532226107 Page 12 of 15 Pages ------------------- ------------------- Item 10. Certification: By signing below, I certify that, to the best of my knowledge and belief, the securities referred to above were acquired and are held in the ordinary course of business and were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect. SIGNATURES 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. SIDUS INVESTMENT PARTNERS, L.P. Date: January 30, 2006 By: /s/ Alfred V. Tobia, Jr. ------------------------ Alfred V. Tobia, Jr., managing member of Sidus Investment Management, LLC, the investment manager By: /s/ Michael J. Barone --------------------- Michael J. Barone, managing member of Sidus Investment Management, LLC, the investment manager SIDUS INVESTMENTS, LTD. Date: January 30, 2006 By: /s/ Alfred V. Tobia, Jr. ------------------------ Alfred V. Tobia, Jr., managing member of Sidus Investment Management, LLC, the investment manager By: /s/ Michael J. Barone --------------------- Michael J. Barone, managing member of Sidus Investment Management, LLC, the investment manager SIDUS INVESTMENT MANAGEMENT, LLC Date: January 30, 2006 By: /s/ Alfred V. Tobia, Jr. ------------------------ Alfred V. Tobia, Jr., managing member By: /s/ Michael J. Barone --------------------- Michael J. Barone, managing member ------------------- ------------------- CUSIP No. 532226107 Page 13 of 15 Pages ------------------- ------------------- ALFRED V. TOBIA, JR. Date: January 30, 2006 By: /s/ Alfred V. Tobia, Jr. ------------------------ MICHAEL J. BARONE Date: January 30, 2006 By: /s/ Michael J. Barone --------------------- ------------------- ------------------- CUSIP No. 532226107 Page 14 of 15 Pages ------------------- ------------------- EXHIBIT 1 -- AGREEMENT OF JOINT FILING In accordance with Rule 13d-1(k) under the Securities Exchange Act of 1934, as amended, the undersigned hereby agrees that the foregoing statement on Schedule 13G/A, is filed on behalf of each of the undersigned and that all subsequent amendments to this statement on Schedule 13G, shall be filed on behalf of each of the undersigned without the necessity of filing additional joint acquisition statements. The undersigned acknowledge that each shall be responsible for the timely filing of such amendments, and for the completeness and accuracy of the information concerning him or it contained therein, but shall not be responsible for the completeness and accuracy of information concerning the others, except to the extent that he or it knows or has reason to believe that such information is inaccurate. IN WITNESS WHEREOF, the undersigned hereby execute this Agreement on the 30th day of January, 2006. SIDUS INVESTMENT PARTNERS, L.P. Date: January 30, 2006 By: /s/ Alfred V. Tobia, Jr. ------------------------ Alfred V. Tobia, Jr., managing member of Sidus Investment Management, LLC, the investment manager By: /s/ Michael J. Barone --------------------- Michael J. Barone, managing member of Sidus Investment Management, LLC, the investment manager SIDUS INVESTMENTS, LTD. Date: January 30, 2006 By: /s/ Alfred V. Tobia, Jr. ------------------------ Alfred V. Tobia, Jr., managing member of Sidus Investment Management, LLC, the investment manager By: /s/ Michael J. Barone --------------------- Michael J. Barone, managing member of Sidus Investment Management, LLC, the investment manager SIDUS INVESTMENT MANAGEMENT, LLC Date: January 30, 2006 By: /s/ Alfred V. Tobia, Jr. ------------------------ Alfred V. Tobia, Jr., managing member By: /s/ Michael J. Barone --------------------- Michael J. Barone, managing member ------------------- ------------------- CUSIP No. 532226107 Page 15 of 15 Pages ------------------- ------------------- ALFRED V. TOBIA, JR. Date: January 30, 2006 By: /s/ Alfred V. Tobia, Jr. ------------------------ MICHAEL J. BARONE Date: January 30, 2006 By: /s/ Michael J. Barone ---------------------