Exhibit
18.1
The
GSI
Group, Inc.
Assumption,
Illinois
We
are
providing this letter to you for inclusion as an exhibit to your Form 10-K
filing pursuant to Item 601 of Regulation S-K.
We
have
read management’s justification for the change in accounting method for the
reclassification of certain distribution costs to cost of goods sold from
selling, general and administrative expenses as contained in the Company’s Form
10-K for the year ended December 31, 2006. Based on our reading of the data
and
discussions with Company officials about the business judgment and business
planning factors relating to the change, we believe management’s justification
to be reasonable. Accordingly, in reliance on management’s determination as
regards elements of business judgment and business planning, we concur that
the
newly adopted accounting principle described above is preferable in the
Company’s circumstances to the method previously applied.
/s/
BKD,
LLP
St.
Louis, Missouri
March
23,
2007