8-K

                                 UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                                    FORM 8-K

                                 CURRENT REPORT
    PURSUANT TO SECTION 13 OR 15 (d) OF THE SECURITIES EXCHANGE ACT OF 1934

Date of Report (Date of earliest event reported):  May 14, 2004

                               GSI LUMONICS INC.
                               -----------------
             (Exact name of registrant as specified in its charter)

     New Brunswick, Canada                                     No. 98-0110412
- -------------------------------   -----------------------   --------------------
(State or other jurisdiction of   (Commission File Number)    I.R.S. Employer
        incorporation)                                      Identification (No.)


             39 Manning Road, Billerica, MA                       01821
        ----------------------------------------               ----------
        (Address of principal executive offices)               (Zip code)

Registrant's telephone number, including area code:  (978) 439-5511

                                      N/A
         -------------------------------------------------------------
         (Former Name or Former Address, if changed since last report)




Item 5.  Regulation FD Disclosures
- ----------------------------------

         On May 17, 2004, GSI Lumonics Inc. ("GSI") issued a press release
announcing the closing of its acquisition of MicroE Systems Corp., a Delaware
corporation ("MicroE"). A copy of the press release is attached as Exhibit 99.1
to this Current Report on Form 8-K and is incorporated herein by reference.



Item 7. Financial Statements, Pro Forma Financial Information and Exhibits
- --------------------------------------------------------------------------


(c) Exhibits

99.1     Press Release dated May 17, 2004.



                                   SIGNATURES

         Pursuant to the requirements of the Securities Exchange Act of 1934,
the registrant has duly caused this report to be signed on its behalf by the
undersigned hereunto duly authorized.

                                         GSI LUMONICS INC.


                                         By: /s/ Thomas R. Swain
                                             ---------------------------------
                                             Thomas R. Swain
                                             Vice President, Finance and Chief
                                             Financial Officer

                                         Date:  May 17, 2004




                                 EXHIBIT INDEX

Exhibit No.       Description

99.1              Press Release dated May 17, 2004

EX-99

                                                                 Exhibit 99.1



GSI Lumonics Announces Acquisition of MicroE Systems

Billerica, MA (May 17, 2004) GSI Lumonics Inc. (NASDAQ: GSLI and TSX: LSI)
today announced the closing of its acquisition of MicroE Systems Corp for an
all-cash purchase price of US$55.0 million, excluding expenses.

MicroE Systems, located in Natick, MA, is recognized as a technology leader in
the design and manufacture of position encoders for precision motion control
applications in data storage, semiconductor and electronics, industrial
automation and medical markets.

Unaudited results of MicroE for the year ended December 31, 2003 were $21
million in revenues and operating income of 5% of revenues. In the most recent
quarter ended April 4, 2004, unaudited results were net revenues of $7.7
million and operating income at 23% of revenues. The unaudited results for
MicroE do not include expected amortization expense that will be determined
from the valuation of intangible assets for the purchase. Backlog at closing
was approximately $8.5 million.

Charles Winston, GSI Lumonics' President and Chief Executive Officer said, "The
addition of MicroE Systems is consistent with our stated acquisition strategy.
We believe MicroE brings key technology and personnel, an impressive new
product stream, a loyal and growing customer base and a real opportunity to
expand our technology offerings with complementary products."
- -------------------------------------------------------------------------------

GSI Lumonics will host a conference call for investors at 5:00 p.m. Eastern
Time on Tuesday, May 18, 2004. To participate, call 800-299-7635 (within the US
and Canada) and 617-786-2901 (for international callers) no earlier than 4:50
p.m. Eastern Time and no later than 4:55 p.m. Eastern Time and identify
yourself to the operator with the participant code of 96556130. A replay of the
call will be available one hour after the call ends to midnight, June 1, 2004
by dialing 888-286-8010 (within the US and Canada) or 617-801-6888 (for
international callers). The access code is 59070009.

The conference call also will be broadcast live over the Internet in
listen-only mode. For live webcasting, go to http://phx.corporate-ir.net/
phoenix.zhtml?c=75037&p=IROL-eventDetails&EventId=894180 at least 15 minutes
prior to the call in order to register download and install any necessary
software. The call will be archived on the above web site until midnight,
June 1, 2004.


- -------------------------------------------------------------------------------
GSI Lumonics supplies precision motion control components, lasers and
laser-based advanced manufacturing systems to the global medical,
semiconductor, electronics, and industrial markets. GSI Lumonics' common shares
are listed on NASDAQ (GSLI) and The Toronto Stock Exchange (LSI).



Certain statements in this news release may constitute forward-looking
statements within the meaning of the United States Private Securities
Litigation Reform Act of 1995, Section 27A of the United States Securities Act
of 1933 and Section 21E of the United States Securities Exchange Act of 1934.
These forward-looking statements may relate to anticipated financial
performance, management's plans and objectives for future operations, business
prospects, outcome of regulatory proceedings, market conditions, tax issues and
other matters. All statements contained in this news release that do not relate
to matters of historical fact should be considered forward-looking statements,
and are generally identified by words such as "anticipate," "believe,"
"estimate," "expect," "intend," "plan," "objective" and other similar
expressions. Readers should not place undue reliance on the forward-looking
statements contained in this news release. Such statements are based on
management's beliefs and assumptions and on information currently available to
management and are subject to risks, uncertainties and changes in condition,
significance, value and effect. Other risks include the fact that the Company's
sales have been and are expected to continue to be dependent upon customer
capital equipment expenditures, which are, in turn, affected by business cycles
in the markets served by those customers. Other factors include volatility in
the semiconductor industry, the risk of order delays and cancellations, the
risk of delays by customers in introducing their new products and market
acceptance of products incorporating subsystems supplied by the Company,
similar risks to the Company of delays in its new products, our ability to
continue to reduce costs and capital expenditures, our ability to focus R&D
investment and integrate acquisitions and other risks detailed in reports and
documents filed by the Company with the United States Securities and Exchange
Commission and with securities regulatory authorities in Canada. Such risks,
uncertainties and changes in condition, significance, value and effect, many of
which are beyond the Company's control, could cause the Company's actual
results and other future events to differ materially from those anticipated.
The Company does not, however, assume any obligation to update these
forward-looking statements to reflect actual results, changes in assumptions or
changes in other factors affecting such forward-looking statements.


For more information contact:
Investor Relations, 613-224-4868, Ann Dempsey, (ext. 2#)