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EXHIBIT 10.3

                                SECOND AMENDMENT
                              OF PURCHASE AGREEMENT

     THIS SECOND AMENDMENT OF PURCHASE AGREEMENT ("Agreement"), made and entered
into to be effective as of the 29th day of December, 2005, by and between GSI
GROUP CORPORATION, a Michigan corporation ("Seller"), and STAG II MAPLE GROVE,
LLC, a Delaware limited liability company (as successor to SAgE Aggregation,
LLC, "Purchaser").

                                    RECITALS

     A. In that certain Real Estate Purchase and Sale Agreement with an
Effective Date of November 14, 2005 as amended by that certain Amendment of
Purchase Agreement effective as of December 26, 2005 (as so amended, "Purchase
Agreement") by and between Seller, as seller, and Purchaser, as purchaser,
Seller has agreed to sell to Purchaser and Purchaser has agreed to purchase from
Seller certain real property lying and being in the County of Hennepin, State of
Minnesota ("Property") as legally described in the Purchase Agreement.

     B. Seller and Purchaser have agreed to amend the Closing Date (as defined
in the Purchase Agreement) and the last day of the Study Period (as defined in
the Purchase Agreement) to January 5, 2006.

     NOW, THEREFORE, in consideration of the foregoing and other good and
valuable consideration, the receipt of which is hereby acknowledged, Seller and
Purchaser hereby agree as follows:

     1. Recitals a Part Hereof. The Recitals set forth above shall be deemed a
part of this Agreement and are hereby incorporated herein by reference.

     2. Amendment. All parties hereto agree that (i) "Closing Date" (as defined
in the Purchase Agreement) shall be amended to "January 5, 2006" and (ii) the
Study Period (as defined in the Purchase Agreement) shall be amended to end on
January 5, 2006.

     3. Binding Effect; Consistency. The Purchase Agreement, as amended hereby,
shall continue in full force and effect, subject to the terms and provisions
thereof and hereof. In the event of any conflict between the terms of the
Purchase Agreement and the terms of this Agreement, the terms of this Agreement
shall control. This Agreement shall be binding upon and inure to the benefit of
Seller, Purchaser, and their respective successors and permitted assigns.

     4. Counterparts. This Agreement may be executed in counterparts, all of
which, when taken together, shall constitute one and the same original.

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     IN WITNESS WHEREOF, the parties hereto have executed this Agreement to be
effective as of the date and year first above written.

                                        GSI GROUP CORPORATION,
                                        a Michigan corporation


                                        By:
                                            ------------------------------------
                                        Name: Robert L. Bowen
                                        Its: Chief Financial Officer

                       [SIGNATURES CONTINUE ON NEXT PAGE]

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                                        STAG II MAPLE GROVE, LLC,
                                        a Delaware limited liability company


                                        By:
                                            ------------------------------------
                                        Name: Benjamin S. Butcher
                                        Title: President