SECURITIES & EXCHANGE COMMISSION
                             Washington, D.C. 20549
                             ----------------------

                                 SCHEDULE 13D/A*

                                (Amendment No. 5)

                                 GSI GROUP INC.
             ------------------------------------------------------
                                (Name of Issuer)

                                  COMMON STOCK
             ------------------------------------------------------
                         (Title of Class of Securities))

                                    36229U102
             ------------------------------------------------------
                                 (CUSIP NUMBER)

                                   John Oliva
                       Highbridge Capital Management, LLC
                         9 West 57th Street, 27th Floor
                            New York, New York 10019
             ------------------------------------------------------
                  (Name, address and telephone number of person
                authorized to receive notices and communications)

                                   May 7, 2010
             ------------------------------------------------------
            (Date of event which requires filing of this statement))

     If the filing person has previously filed a statement on Schedule 13G to
report the acquisition which is the subject of this Schedule 13D, and is filing
this schedule because of Rule 13d-1(e), 13d-1(f) or 13d-1(g), check the
following box [ ].

     NOTE: Schedules filed in paper format shall include a signed original and
five copies of the schedule, including all exhibits. See Rule 13d-7 for other
parties to whom copies are to be sent.

                         (Continued on following pages)

                               (Page 1 of 8 Pages)

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     (1)The remainder of this cover page shall be filled out for a reporting
person's initial filing on this form with respect to the subject class of
securities, and for any subsequent amendment containing information which would
alter the disclosures provided in a prior cover page.

     The information required in the remainder of this cover page shall not be
deemed to be "filed" for purposes 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 (however, see the
Notes).




CUSIP No. 36229U102                      13D/A                       Page 2 of 8

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     (1)    NAME OF REPORTING PERSONS

                    Highbridge Capital Management, LLC

--------------------------------------------------------------------------------
     (2)    CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP
                                                                  (a)  [ ]
                                                                  (b)  [X]

--------------------------------------------------------------------------------
     (3)    SEC USE ONLY

--------------------------------------------------------------------------------
     (4)    SOURCE OF FUNDS
                            OO

--------------------------------------------------------------------------------
     (5)    CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS
            REQUIRED PURSUANT TO ITEMS 2(d) OR 2(e)                       [ ]

--------------------------------------------------------------------------------
     (6)    CITIZENSHIP OR PLACE OF ORGANIZATION
                    Delaware

--------------------------------------------------------------------------------
NUMBER OF      (7)  SOLE VOTING POWER
                    -0-
SHARES         -----------------------------------------------------------------

BENEFICIALLY   (8)  SHARED VOTING POWER
                    1,325,136 shares of Common Stock
OWNED BY       -----------------------------------------------------------------

EACH           (9)  SOLE DISPOSITIVE POWER
                    -0-
REPORTING      -----------------------------------------------------------------

PERSON WITH    (10) SHARED DISPOSITIVE POWER
                    1,325,136 shares of Common Stock

--------------------------------------------------------------------------------
     (11)   AGGREGATE AMOUNT BENEFICIALLY OWNED
            BY EACH REPORTING PERSON
            1,325,136 shares of Common Stock

--------------------------------------------------------------------------------
     (12)   CHECK BOX IF THE AGGREGATE AMOUNT
            IN ROW (11) EXCLUDES CERTAIN SHARES **                       [ ]

--------------------------------------------------------------------------------
     (13)   PERCENT OF CLASS REPRESENTED
            BY AMOUNT IN ROW (11)
                    2.8% (See Item 4)

--------------------------------------------------------------------------------
     (14)   TYPE OF REPORTING PERSON
                    OO

--------------------------------------------------------------------------------




CUSIP No. 36229U102                      13D/A                       Page 3 of 8

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     (1)    NAME OF REPORTING PERSONS

                    Highbridge International LLC

--------------------------------------------------------------------------------
     (2)    CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP
                                                                  (a)  [ ]
                                                                  (b)  [X]

--------------------------------------------------------------------------------
     (3)    SEC USE ONLY

--------------------------------------------------------------------------------
     (4)    SOURCE OF FUNDS
                    WC

--------------------------------------------------------------------------------
     (5)    CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS
            REQUIRED PURSUANT TO ITEMS 2(d) OR 2(e)                       [ ]

--------------------------------------------------------------------------------
     (6)    CITIZENSHIP OR PLACE OF ORGANIZATION
                    Cayman Islands, British West Indies

--------------------------------------------------------------------------------
NUMBER OF      (7)  SOLE VOTING POWER
                    -0-
SHARES         -----------------------------------------------------------------

BENEFICIALLY   (8)  SHARED VOTING POWER
                    1,325,136 shares of Common Stock
OWNED BY       -----------------------------------------------------------------

EACH           (9)  SOLE DISPOSITIVE POWER
                    -0-
REPORTING      -----------------------------------------------------------------

PERSON WITH    (10) SHARED DISPOSITIVE POWER
                    1,325,136 shares of Common Stock

--------------------------------------------------------------------------------
     (11)   AGGREGATE AMOUNT BENEFICIALLY OWNED
            BY EACH REPORTING PERSON
            1,325,136 shares of Common Stock

--------------------------------------------------------------------------------
     (12)   CHECK BOX IF THE AGGREGATE AMOUNT
            IN ROW (11) EXCLUDES CERTAIN SHARES                        [ ]

--------------------------------------------------------------------------------
     (13)   PERCENT OF CLASS REPRESENTED
            BY AMOUNT IN ROW (11)
                    2.8% (See Item 4)

--------------------------------------------------------------------------------
     (14)   TYPE OF REPORTING PERSON
                    OO

--------------------------------------------------------------------------------




CUSIP No. 36229U102                      13D/A                       Page 4 of 8

--------------------------------------------------------------------------------

     (1)    NAME OF REPORTING PERSONS

                    Glenn Dubin

--------------------------------------------------------------------------------
     (2)    CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP
                                                                  (a)  [ ]
                                                                  (b)  [X]

--------------------------------------------------------------------------------
     (3)    SEC USE ONLY

--------------------------------------------------------------------------------
     (4)    SOURCE OF FUNDS
                    OO

--------------------------------------------------------------------------------
     (5)    CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS
            REQUIRED PURSUANT TO ITEMS 2(d) OR 2(e)                       [ ]

--------------------------------------------------------------------------------
     (6)    CITIZENSHIP OR PLACE OF ORGANIZATION
                    United States

--------------------------------------------------------------------------------
NUMBER OF      (7)  SOLE VOTING POWER
                    -0-
SHARES         -----------------------------------------------------------------

BENEFICIALLY   (8)  SHARED VOTING POWER
                    1,325,136 shares of Common Stock
OWNED BY       -----------------------------------------------------------------

EACH           (9)  SOLE DISPOSITIVE POWER
                    -0-
REPORTING      -----------------------------------------------------------------

PERSON WITH    (10) SHARED DISPOSITIVE POWER
                    1,325,136 shares of Common Stock

--------------------------------------------------------------------------------
     (11)   AGGREGATE AMOUNT BENEFICIALLY OWNED
            BY EACH REPORTING PERSON
                    1,325,136 shares of Common Stock

--------------------------------------------------------------------------------
     (12)   CHECK BOX IF THE AGGREGATE AMOUNT
            IN ROW (11) EXCLUDES CERTAIN SHARES                        [ ]

--------------------------------------------------------------------------------
     (13)   PERCENT OF CLASS REPRESENTED
            BY AMOUNT IN ROW (11)
                     2.8% (See Item 4)

--------------------------------------------------------------------------------
     (14)   TYPE OF REPORTING PERSON
                    IN

--------------------------------------------------------------------------------




CUSIP No. 36229U102                      13D/A                       Page 5 of 8

Item 1.     Security and Issuer.

     This Amendment No. 5 (the "Amendment") amends the statement on Schedule 13D
filed on July 2, 2009 (the  "Original  Schedule  13D", as amended  hereby and by
Amendment  No. 1 filed on November 20, 2009,  Amendment  No. 2 filed on March 3,
2010, Amendment No. 3 filed on March 16, 2010 and Amendment No. 4 filed on March
19, 2010,  the "Schedule  13D") with respect to the common  stock,  no par value
(the "Common Stock"),  of GSI Group Inc., a company continued and existing under
the laws of the Province of New Brunswick,  Canada (the  "Issuer").  Capitalized
terms used herein and not otherwise  defined in this Amendment have the meanings
set forth in the Schedule  13D.  This  Amendment  amends Items 4, 6 and 7 as set
forth below.


Item 4.     Purpose of the Transaction.

Item 4 of the Schedule 13D is hereby amended and supplemented by the addition of
the following:

On May 7, 2010 Highbridge International and the other Consenting Noteholders
reached an agreement in principle with the Issuer Parties and the statutory
committee of equity security holders appointed on December 22, 2009 in the
bankruptcy cases of the Issuer Parties (the "Equity Committee") as to certain
modifications to the Modified Plan (as modified, the "Fourth Modified Plan of
Reorganization"). The Consenting Noteholders plan to enter into a Restructuring
Plan Support Agreement, which will supersede the Plan Support Agreement, with
the Issuer Parties and the Equity Committee setting forth certain agreements
among them to implement the Fourth Modified Plan of Reorganization (the
"Restructuring Plan Support Agreement").

Pursuant to the Fourth Modified Plan of Reorganization, the Noteholders would
receive, in exchange for their Notes, their pro-rata share of (i) between
$90,000,000 and $110,000,000 principal amount of New Senior Secured Notes, (ii)
$10,000,000 in cash (the "Cash Payment"), (iii) all cash proceeds from an
$85,000,000 rights offering (the "Rights Offering"), (iv) payment in cash of all
accrued but unpaid interest due under the Notes through the date of
effectiveness of the Issuer Parties' bankruptcy cases, and (v) $5,000,000 of
common stock of the reorganized Issuer, issued at a price of $1.80 per share
(the "Supplemental Equity Exchange").

The Rights Offering will consist of the Issuer Parties offering to all holders
of Common Stock, on a pro-rata basis, the right to purchase common stock of the
reorganized Issuer at a price of $1.80 per share. Pursuant to the Restructuring
Plan Support Agreement and related documents, the Consenting Noteholders will
agree to backstop the Rights Offering in its entirety with their Notes.
Therefore, to the extent the Rights Offering is not fully subscribed for by the
holders of Common Stock, the Consenting Noteholders will exchange a principal
amount of their Notes equal to any such shortfall into common stock of the
reorganized Issuer at a price of $1.80 per share. Notwithstanding the foregoing,
in connection with their backstop commitment, the Consenting Noteholders will
exchange no less than $20,000,000 in principal amount of their Notes for common
stock of the reorganized Issuer at $1.80 per share even if their backstop
commitment requires an exchange of less than this amount. For example, if the
holders of Common Stock elect not to participate in the Rights Offering, then
the Noteholders pursuant to their backstop commitment will exchange $85,000,000
in principal amount of Notes




CUSIP No. 36229U102                      13D/A                       Page 6 of 8


for common stock of the reorganized Issuer at a price of $1.80 per share. When
combined with the application of the Cash Payment and Supplemental Equity
Exchange, this will result in the issuance of an aggregate principal amount of
New Senior Secured Notes equal to $110,000,000. However, if the Rights Offering
is fully subscribed for by the holders of Common Stock, the Noteholders will
receive the cash proceeds of the Rights Offering in satisfaction of $85,000,000
principal amount of Notes and the Consenting Noteholders will exchange
$20,000,000 in principal amount of Notes for common stock of the reorganized
Issuer at a price of $1.80 per share. When combined with the application of the
Cash Payment and Supplemental Equity Exchange, this will result in the issuance
of an aggregate principal amount of New Senior Secured Notes equal to
$90,000,000. The Consenting Noteholders will receive a fee of 5% of the backstop
commitment amount in exchange for their commitment to backstop the Rights
Offering.

The Noteholders are entitled to receive a fee equal to 2% of the aggregate
principal amount of Notes currently outstanding in the event that at any time
prior to consummation of the Rights Offering a restructuring transaction other
than the restructuring transaction set forth in the Fourth Modified Plan of
Reorganization is consummated.

Pursuant to the Fourth Modified Plan of Reorganization, the initial board of
directors of the reorganized Issuer will consist of: two directors to be
selected by the Required Noteholders, two directors with expertise in the
Issuer's industry to be selected by the Equity Committee, one director to be
selected by mutual agreement of the Required Noteholders and the Equity
Committee, one director to be selected by the current Board of Directors from
the current Board of Directors of the Issuer, and the Chief Executive Officer of
the reorganized Issuer. The three holders of the largest principal amounts of
the Notes shall have board observer rights subject to reasonable restrictions.

This description of the agreement in principle reached by the Consenting
Noteholders, the Issuer Parties and the Equity Committee is a summary only and
is qualified in its entirety by reference to the Term Sheet for the Plan of
Reorganization of GSI Group, Inc. et al (the "Term Sheet"), a copy of which is
referenced as Exhibit 9 hereto (which incorporates by reference Exhibit 99.1 of
the Current Report on Form 8-K filed by the Issuer on May 11, 2010) and is
incorporated herein by reference.





CUSIP No. 36229U102                      13D/A                       Page 7 of 8


Item 6.      Contracts, Arrangements, Understandings or Relationships with
Respect to Securities of the Issuer

Item 6 of the Schedule 13D is hereby amended and supplemented by the addition of
the following:

     As described in Item 4 above, on May 7, 2010, the Consenting Noteholders
reached an agreement in principle with the Issuer Parties and the Equity
Committee as to the Fourth Modified Plan of Reorganization, the terms of which
are set forth in the Term Sheet a copy of which is referenced as Exhibit 9
hereto (which incorporates by reference Exhibit 99.1 of the Current Report on
Form 8-K filed by the Issuer on May 11, 2010) and is incorporated herein by
reference.

Item 7.     Material to Be Filed as Exhibits

Item 7 of the Schedule 13D is hereby amended and supplemented by the addition of
the following:

9. Term Sheet for the Plan of Reorganization of GSI Group, Inc. et al, dated as
of May 7, 2010 (incorporated by reference to Exhibit 99.1 of the Current Report
on Form 8-K filed by the Issuer on May 11, 2010).













CUSIP No. 36229U102                      13D/A                       Page 8 of 8


SIGNATURES

After reasonable inquiry and to the best of our knowledge and belief, the
undersigned certify that the information set forth in this statement is true,
complete and correct.


DATED:  May 11, 2010

HIGHBRIDGE INTERNATIONAL LLC                  HIGHBRIDGE CAPITAL MANAGEMENT, LLC

By: Highbridge Capital Management, LLC
    its Trading Manager                       By: /s/ John Oliva
                                                  -------------------------
                                              Name: John Oliva
                                              Title: Managing Director

By: /s/ John Oliva
    -------------------------
Name: John Oliva
Title: Managing Director




/s/ Glenn Dubin
-------------------------
GLENN DUBIN