Exhibit 10.51  GT Solar
International, Inc. 243
Daniel Webster Highway
Merrimack, New Hampshire 03054  EMPLOYMENT
AGREEMENT AMENDMENT FOR CODE SECTION 409A  December 30,
2008  John Tattersfield 519 Bay Road South Easton, MA
02375  Dear Mr. Tattersfield,  This letter agreement
(the Amendment) shall amend the Employment Agreement(the Employment Agreement), dated
as of August 6, 2007, between you (the Executive) and GT Solar
International, Inc. (the Company).  All capitalized terms not otherwise defined
herein shall have the meanings ascribed to them in the Employment
Agreement.  Except as modified by this
Amendment, the Employment Agreement shall remain in full force and effect, and
this Amendment shall not serve in any manner as a waiver or a novation of the
Executives duties or obligations under the Employment Agreement; provided,
that in the event that any provision in this Amendment conflicts with the
Employment Agreement or any other agreement, policy, plan or arrangement
between the Executive and the Company, the terms of this Amendment shall
govern.  You
agree and acknowledge that notwithstanding any other provision of the
Employment Agreement to the contrary, the Employment Agreement is hereby
amended as follows:  1.Paragraph 3(e) of the Employment
Agreement is amended as follows:  Following the
phrase provided, however, the text that the Executive must
remain employed by the Company until each such Anniversary Date in order to
receive each such payment; provided, further, shall be added to
first sentence of paragraph 3(e).  2.Clause (i) of paragraph 4(b) of
the Employment Agreement is amended and restated in its entirety as follows:  (i) continue
to receive his Base Salary (paid in accordance with the Companys general
payroll practices in effect on the Termination Date) as special severance
payments from the Termination Date for a period of six (6) months
thereafter (the Severance Period) as provided in paragraph 4(h) below
and delayed as required in paragraph 4(i) below (the date on which
Executives employment under this Agreement terminates for any reason shall be
referred herein as the Termination Date); and  3.Clause (iv) of paragraph 4(b) of
the Employment Agreement is amended as follows:


The parenthetical
at the end of the first sentence beginning provided that if any stock of the
Company and concluding if earlier, upon Executives death is deleted and
replaced with the non-parenthetical clause and subject to the provisions of
paragraph 4(h) and 4(i) below.  4.A new paragraph 4(h) is added to the
Employment Agreement as follows:  (h)Once the Mutual Release described in
paragraph 4(b) is executed and no longer subject to revocation then the
following shall apply: (i)To the extent any cash payment or
continuing benefit to be provided under paragraph 4(b) is not deferred
compensation for purposes of Internal Revenue Code Section 409A and the
regulations and guidance promulgated thereunder (collectively Code Section 409A),
then such payment or benefit shall commence upon the first scheduled payment
date immediately after the date the Mutual Release is executed and no longer
subject to revocation (the Release Effective Date).  The first such cash payment shall include
payment of all amounts that otherwise would have been due prior to the Release
Effective Date under the terms of this Agreement applied as though such
payments commenced immediately upon the Termination Date, and any payments made
thereafter shall continue as provided herein. 
The delayed benefits shall in any event expire at the time such benefits
would have expired had such benefits commenced immediately following the
Termination Date.  (ii)To the extent any cash payment or
continuing benefit to be provided under paragraph 4(b) is deferred
compensation for purposes of Code Section 409A, then such payments or
benefits shall be made or commence upon the sixtieth (60) day following the
Termination Date.  The first such cash
payment shall include payment of all amounts that otherwise would have been due
prior thereto under the terms of this Agreement had such payments commenced
immediately upon Executives termination of employment, and any payments made
thereafter shall continue as provided herein.  5.A new paragraph 4(i) is added to the
Employment Agreement as follows:  (i)Section 409A
Compliance. (i)The intent of the parties is that
payments and benefits under this Agreement comply with Code Section 409A
and, accordingly, to the maximum extent permitted, this Agreement shall be
interpreted to be in compliance therewith. 
In no event whatsoever shall the Company be liable for any additional
tax, interest or penalty that may be imposed on Executive by Code Section 409A
or damages for failing to comply with Code Section 409A.  2


(ii)A termination of employment shall not be
deemed to have occurred for purposes of any provision of this Agreement
providing for the payment of any amounts or benefits upon or following a
termination of employment unless such termination is also a separation from
service within the meaning of Code Section 409A and, for purposes of any
such provision of this Agreement, references to a termination, termination
of employment or like terms shall mean separation from service.  (iii)Notwithstanding any other payment
schedule provided herein to the contrary, if Executive is deemed on the date of
termination to be a specified employee within the meaning of that term under
Code Section 409A(a)(2)(B), then each of the following shall apply:  (A)With regard to any
payment that is considered deferred compensation under Code Section 409A
payable on account of a separation from service, such payment shall be made
on the date which is the earlier of (A) the expiration of the six
(6)-month period measured from the date of such separation from service of
Executive, and (B) the date of Executives death (the Delay Period)
to the extent required under Code Section 409A.  Upon the expiration of the Delay Period, all
payments delayed pursuant to this paragraph 4(i) (whether they would have
otherwise been payable in a single sum or in installments in the absence of
such delay) shall be paid to Executive in a lump sum, and all remaining
payments due under this Agreement shall be paid or provided in accordance with
the normal payment dates specified for them herein; and  (B)To the extent that any
benefits to be provided during the Delay Period is considered deferred
compensation under Code Section 409A provided on account of a separation
from service, and such benefits are not otherwise exempt from Code Section 409A,
Executive shall pay the cost of such benefits during the Delay Period, and the
Company shall reimburse Executive, to the extent that such costs would
otherwise have been paid by the Company or to the extent that such benefits
would otherwise have been provided by the Company at no cost to Executive, the
Companys share of the cost of such benefits upon expiration of the Delay
Period, and any remaining benefits shall be reimbursed or provided by the
Company in accordance with the procedures specified herein.  (iv)To the extent that any agreement provides
for the reimbursement of expenses or the provision of in-kind benefits that
constitute non-qualified deferred compensation under Code Section 409A,
the following shall apply: (i) all expenses or other reimbursements under
an agreement shall be made on or prior to the last day of the taxable year
following the  3


taxable year in which such expenses were incurred by
Executive; (2) any right to reimbursement or in kind benefits is not
subject to liquidation or exchange for another benefit; and (3) no such
reimbursement, expenses eligible for reimbursement, or in-kind benefits provided
in any taxable year shall in any way affect the expenses eligible for
reimbursement, or in-kind benefits to be provided, in any other taxable year.  (v)For purposes of Code Section 409A,
Executives right to receive any installment payment pursuant to this Agreement
shall be treated as a right to receive a series of separate and distinct
payments.  (vi)Notwithstanding any other provision of
this Agreement to the contrary, in no event shall any payment under this
Agreement that constitutes deferred compensation for purposes of Code Section 409A
be subject to offset by any other amount unless otherwise permitted by Code Section 409A.  6.Paragraph 21 of the Employment Agreement
is amended as follows:  Following the
phrase and/or the receipt or vesting of restricted the following is added to
the paragraph: equity).  In the event
the Company or any of its Subsidiaries does not make such deductions or
withholdings, Executive shall indemnify the Company and its Subsidiaries for
any amounts paid with respect to any such Taxes, together with any interest,
penalties and related expenses thereto.  [Signature page follows]  4


Sincerely,GT SOLAR INTERNATIONAL,
  INC./s/Brian P. LogueBy: Brian P. LogueIts: Vice President
  Human ResourcesACCEPTED AND AGREED:/s/John TattersfieldJohn TattersfieldDate:
  December 30, 2008  5