Exhibit 4.5

                              GCA CORPORATION

                           REGISTRATION AGREEMENT
                           ----------------------

          Registration Agreement, dated as of April 23, 1987, among GCA
Corporation, a Delaware corporation (the "Company"), and each of the banks
and insurance companies listed on the signature pages hereof, and Carl
Zeiss, Inc. (individually, a "Lender" and collectively, the "Lender
Group"). Terms not otherwise defined herein shall have the meaning ascribed
to them in the Warrant Agreement.

                            W I T N E S S E T H
                            - - - - - - - - - -

          WHEREAS, The Hallwood Group Incorporated, a Delaware corporation
("Hallwood"), and the Lender Group (other than TIAA) are parties to that
certain Restructuring Agreement, dated as of December 5, 1986 (the
"Restructuring Agreement"), as amended; and

          WHEREAS, Hallwood and Teachers Insurance & Annuity Association of
America ("TIAA") are parties to that certain letter agreement dated
December 5, 1986; and

          WHEREAS, the Company and the Lender Group are parties to that
certain Warrant Agreement of even date herewith (the "Warrant Agreement"),
pursuant to which the Company has issued to the Lender Group warrants (the
"Warrants") to purchase 2,190,806 shares (after giving effect to the
1-for-50 reverse stock split of the common stock (as hereinafter defined)
contemplated to occur on April 24, 1987) of common stock, $.01 par value
per share, of the Company (the "Common Stock"); and

          WHEREAS, the Warrant Agreement provides that at the Closing the
Company and the Lender Group shall execute and deliver this Agreement;

          NOW, THEREFORE, in consideration of the premises and of the
mutual covenants hereinafter set forth, the Company and the Lender Group
agree as follows:

          1. Defined Terms. Capitalized terms used in this Agreement,
unless separately defined herein, shall have the meanings ascribed to such
terms in the Restructuring Agreement or the Warrant Agreement.

          2. Demand Registrations. (a) At any time after the Closing, the
holders of at least 20% of the Warrant Shares outstanding at the time
(equitably adjusted to reflect stock splits, stock dividends, combinations
or similar events and adjustments pursuant to Paragraph 5 of the Warrants)
may request registration under the Securities Act of 1933, as amended (the
"Securities Act"), of all or part of their Warrant Shares on Form S-1 or
any other form available for the registration of the Warrant Shares
("Demand Registrations"). Within 10 days after receipt of any such request,
the Company shall give written notice of such request to all other holders
of the Warrant Shares and shall, subject to the provisions of Section 2(c)
hereof, include in such registration all Warrant Shares with respect to
which the Company has received written requests for inclusion therein
within 30 days after the receipt of the Company's notice.

          (b) Subject to the provisions of Section 2(a), the holders of the
Warrant Shares shall be entitled to request three Demand Registrations, and
the Company shall pay all Registration Expenses (as defined in Section 6
hereof) in connection therewith. A registration shall not count as one of
the three permitted Demand Registrations (i) until the registration has
become effective, or (ii) if the holders initiating the request for such
registration are not able to register and sell at least 66-2/3% of the
shares of Common Stock requested by such holders to be included in such
registration. In any event, the Company shall pay all Registration Expenses
in connection with any registration initiated as a Demand Registration,
whether or not consummated.

          (c) In the event that the managing underwriters of the requested
Demand Registration advise the Company in writing that in their judgment in
order to effect an orderly public distribution the number of Warrant Shares
proposed to be included in any such Demand Registration must be limited,
the Company shall include in such registration only the number of Warrant
Shares which, in the opinion of such underwriters, can be sold in an
orderly public distribution, such limitation to be imposed pro rata among
the holders of the Warrant Shares who are participating in such
registration on the basis of the amount of such securities initially
proposed to be registered by such holder.

          (d) The Company shall not be obligated to effect any Demand
Registration within six months after the effective date of a previous
Demand Registration or a previous registration under which each holder of
Warrant Shares was given piggyback rights (and was able to include a
minimum of 66-2/3% of the shares of Warrant Shares requested by it to be
included in such registration) pursuant to Section 3 hereof. The Company
may postpone for up to six months the filing or the effectiveness of a
registration statement for a Demand Registration if the Company reasonably
believes that such Demand Registration might reasonably be expected to have
an adverse effect on any proposal or plan by the Company to engage in any
acquisition of assets (other than in the ordinary course of business) or
any merger, consolidation, tender offer or similar transaction; provided,
however, that in such event, the holders of the Warrant Shares initiating
the request for such Demand Registration shall be entitled to withdraw such
request and, if such request is withdrawn, such Demand Registration shall
not count as one of the permitted Demand Registrations. If the Company
elects to postpone the filing or effectiveness of a Demand Registration, it
shall promptly notify each member of the Lender Group. In any event, the
Company shall pay all Registration Expenses in connection with any
registration initiated as a Demand Registration.

          (e) The holders of a majority of the Warrant Shares participating
in any Demand Registration shall have the right to select the investment
banker(s) and manager(s) to administer the offering, subject to the
Company's approval, which shall not be unreasonably withheld.

          3. Piggyback Registrations. (a) Whenever the Company proposes to
register any of its equity securities under the Securities Act (other than
pursuant to a Demand Registration) and the registration form to be used may
be used for the registration of Warrant Shares (a "Piggyback
Registration"), the Company shall give prompt written notice to all holders
of Warrant Shares of its intention to effect such a registration and shall
include in such registration all Warrant Shares with respect to which the
Company has received written requests for inclusion therein within 30 days
after the receipt of the Company's notice.

          (b) The Registration Expenses of the holders of Warrant Shares
shall be paid by such holders in all Piggyback Registrations.

          (c) If a Piggyback Registration is an underwritten primary
registration on behalf of the Company, and the managing underwriters advise
the Company in writing that in their judgment the number of securities
requested to be included in such registration must be limited in order to
effect an orderly public distribution, the Company shall include in such
registration (i) first, the securities the Company proposes to sell, (ii)
second, the Warrant Shares requested to be included in such registration,
pro rata among the holders of such securities on the basis of the number of
shares initially proposed to be registered by such holders, and (iii)
third, any other securities requested to be included in such registration.

          (d) If a Piggyback Registration is an underwritten secondary
registration on behalf of holders of the Company's securities other than
the holders of the Warrant Shares, and the managing underwriters advise the
Company in writing that in their judgment the number of securities
requested to be included in such registration must be limited in order to
effect an orderly public distribution, the Company shall include in such
registration (i) first, the securities requested to be included therein by
the holders requesting such registration (ii) second, the Warrant Shares
requested to be included in such registration, pro rata among the holders
of such securities on the basis of the number of shares initially proposed
to registered by such holders, and (iii) third, any other securities
requested to be included in such registration.

          4. Holdback Agreements. (a) Each holder of Warrant Shares agrees
not to effect any public sale or distribution of the Warrant Shares owned
by such holder, including, without limitation, sales pursuant to Rule 144
(or any similar rule then in effect), during the 10 days prior to and the
90 days beginning on the effective date of any underwritten Demand
Registration or any underwritten Piggyback Registration in which Warrant
Shares owned by such holder, are included (except as part of such
underwritten registration) unless the underwriters managing the registered
public offering otherwise agree.

          (b) The Company agrees not to effect any public sale or
distribution of its equity securities, or any securities convertible into
or exchangeable or exercisable for such securities, during the 10 days
prior to and during the 90 days beginning on the effective date of any
underwritten Demand Registration or any underwritten Piggyback Registration
(except as part of such underwritten registration or pursuant to
registrations on Form S-8 or any successor form) unless the underwriters
managing the registered public offering otherwise agree.

          5. Registration Procedures. Whenever the holders of the Warrant
Shares have requested that any Warrant Shares be registered pursuant to
this Agreement, the Company shall use its best efforts to effect the
registration of such Warrant Shares in accordance with the intended method
of disposition thereof, and pursuant thereto the Company shall as
expeditiously as possible:

          (a) prepare and file with the Securities and Exchange Commission
a registration statement with respect to such Warrant Shares and use its
best efforts to cause such registration statement to become effective
(provided that before filing a registration statement or prospectus or any
amendments or supplements thereto, the Company will furnish to the counsel
selected by the holders of a majority of the Warrant Shares requesting such
registration statement copies of all documents proposed to be filed, which
documents will be subject to the review of such counsel);

          (b) prepare and file with the Securities and Exchange Commission
such amendments and supplements to such registration statement and the
prospectus used in connection therewith as may be necessary to keep such
registration statement effective for a period of not less than 90 days and
comply with the provisions of the Securities Act with respect to the
disposition of all securities covered by such registration statement during
such period in accordance with the intended methods of disposition by the
sellers thereof set forth in such registration statement;

          (c) furnish to each seller of Warrant Shares such number of
copies of such registration statement, each amendment and supplement
thereto, the prospectus included in such registration statement (including
each preliminary prospectus) and such other documents as such seller may
reasonably request in order to facilitate the disposition of the Warrant
Shares owned by such seller;

          (d) use its best efforts to register or qualify such Warrant
Shares under such other securities or blue sky laws of such jurisdictions
as any seller reasonably requests and do any and all other acts and things
which may be reasonably necessary or advisable to enable such seller to
consummate the disposition in such jurisdictions of the Warrant Shares
owned by such seller (provided that the Company will not be required to (i)
qualify generally to do business in any jurisdiction where it would not
otherwise be required to qualify but for this subparagraph (d), (ii)
subject itself to taxation in any such jurisdiction or (iii) consent to
general service of process in any such jurisdiction);

          (e) notify each seller of such Warrant Shares at any time when a
prospectus relating thereto is required to be delivered under the
Securities Act, of the occurrence of any event as a result of which the
prospectus included in such registration statement contains an untrue
statement of a material fact or omits any fact necessary to make the
statements therein not misleading, and shall prepare in sufficient
quantities a supplement or amendment to such prospectus so that, as
thereafter delivered to the purchasers of such Warrant Shares such
prospectus shall not contain an untrue statement of a material fact or omit
to state any fact necessary to make the statements therein not misleading;

          (f) use its best efforts to cause all such Warrant Shares to be
listed on each securities exchange on which similar securities issued by
the Company are then listed, and provide a transfer agent and registrar for
such securities not later than the effective date of the applicable
registration statement;

          (g) in the case of an underwritten offering, enter into such
customary agreements (including underwriting agreements in customary form)
and take all such other actions as the holders of a majority of the Warrant
Shares being sold or the underwriters, reasonably request in order to
expedite or facilitate the disposition of such Warrant Shares (including,
without limitation, effecting a stock split or a combination of shares);

          (h) make available for inspection by any seller of Warrant
Shares, any underwriter participating in any disposition pursuant to such
registration statement, and any attorney, accountant or other agent
retained by any such seller or underwriter, all financial and other
records, pertinent corporate documents and properties of the Company, and
cause the Company's officers, directors, employees and independent
accountants to supply all information reasonably requested by any such
seller, underwriter, attorney, accountant or agent in connection with such
registration statement; and

          (i) use its best efforts to obtain an appropriate opinion from
the Company's counsel and a comfort letter from the Company's independent
public accountants in customary form and covering such matters of the type
customarily covered by opinions of Company counsel and comfort letters in
similar registrations as the holders of a majority of the Warrant Shares
being sold reasonably request (provided that such holders constitute the
holders of a majority of the securities covered by such registration
agreement).

          If any such registration statement refers to any holder by name
or otherwise as the holder of any securities of the Company, such holder
shall have the right to require (i) the insertion therein of language, in
form and substance reasonably satisfactory to such holder, to the effect
that the holding by such holder of such securities is not to be construed
as a recommendation of such holder of the investment quality of the
Company's securities covered thereby and that such holding does not imply
that such holder will assist in meeting any future financial requirements
of the Company, or (ii) in the event that such reference to such holder by
name or otherwise is not required by the Securities Act or any similar
Federal statute then in force, the deletion of the reference to such
holder.

          6. Registration Expenses. (a) All expenses incident to the
Company's performance of or compliance with this Agreement, including
without limitation, all registration and filing fees, National Association
of Securities Dealers, Inc. fees and expenses of compliance with securities
or blue sky laws, printing expenses, messenger and delivery expenses, and
fees and disbursements of counsel for the Company, all independent
certified public accountants, and underwriters (excluding discounts and
commissions) (all such expenses being herein called "Registration
Expenses"), shall be borne as provided in this Agreement, except that the
Company shall, in any event, pay its internal expenses (including, without
limitation, all salaries and expenses of its officers and employees
performing legal or accounting duties), the expense of any annual audit or
quarterly review, the expense of any liability insurance and the expenses
and fees for listing the securities to be registered on each securities
exchange on which similar securities issued by the Company are then listed.

          (b) In connection with each Registration initiated as a Demand
Registration, the Company shall reimburse the holders of the Warrant Shares
covered by such registration for the reasonable fees and disbursements of
one law firm chosen by the holders of a majority of the Warrant Shares
included in such registration.

          (c) To the extent Registration Expenses are not required to be
paid by the Company, each holder of securities included in any registration
hereunder shall pay the Registration Expenses allocable to the registration
of such holder's securities so included, and any Registration Expenses not
so allocable shall be borne by all sellers of securities included in such
registration in proportion to the aggregate selling price of the securities
to be so registered.

          7. Indemnification. (a) The Company agrees to indemnify, to the
extent permitted by law, each holder of Warrant Shares, its officers and
directors and each Person who controls such holder (within the meaning of
the Securities Act), against all losses, claims, damages, liabilities and
expenses caused by, resulting from, arising out of or based upon any untrue
or alleged untrue statement of material fact contained in any registration
statement, prospectus or preliminary prospectus or any amendment thereof or
supplement thereto or any omission or alleged omission of a material fact
required to be stated therein or necessary to make the statements therein
not misleading, except insofar as the same are caused by, resulting from,
arising out of or based upon or contained in any information furnished in
writing to the Company by such holder expressly for use therein or by such
holder's failure to deliver a copy of the registration statement or
prospectus or any amendments or supplements thereto after the Company has
furnished such holder with a sufficient number of copies of the same. In
connection with an underwritten offering, the Company shall indemnify such
underwriters, their officers and directors and each Person who controls
such underwriters (within the meaning of the Securities Act) to the same
extent as provided above with respect to the indemnification of the holders
of Warrant Shares.

          (b) In connection with any registration statement in which a
holder of Warrant Shares is participating, each such holder shall furnish
to the Company in writing such information and affidavits as the Company
reasonably requests for use in connection with any such registration
statement or prospectus and, to the extent permitted by law, shall
indemnify each other holder of Warrant Shares, the Company, its directors
and officers and each person who controls the Company (within the meaning
of the Securities Act) against any losses, claims, damages, liabilities and
expenses caused by, resulting from, arising out of or based upon any untrue
or alleged untrue statement of material fact contained in the registration
statement, prospectus or preliminary prospectus or any amendment thereof or
supplement thereto or any omission or alleged omission of a material fact
required to be stated therein or necessary to make the statements therein
not misleading, but only to the extent that such untrue statement or
omission is contained in any information or affidavit so furnished in
writing by such holder expressly for use in the registration statement;
provided, however, that the obligation to indemnify shall be several, not
joint and several, among such holders of Warrant Shares and the liability
of each such holder of Warrant Shares, shall be in proportion to and
limited to the net amount received by such holder from the sale of Warrant
Shares pursuant to such registration statement.

          (c) Any person entitled to indemnification hereunder shall (i)
give prompt written notice to the indemnifying party of any claim with
respect to which it seeks indemnification and (ii) unless in such
indemnified party's reasonable judgment a conflict of interest between such
indemnified and indemnifying parties may exist with respect to such claim,
permit such indemnifying party to assume the defense of such claim with
counsel reasonably satisfactory to the indemnified party. If such defense
is assumed, the indemnifying party shall not be subject to any liability
for any settlement made by the indemnified party without its consent (but
such consent will not be unreasonably withheld). An indemnifying party who
is not entitled to, or elects not to, assume the defense of a claim shall
not be obligated to pay the fees and expenses of more than one counsel for
all parties indemnified by such indemnifying party with respect to such
claim, unless in the reasonable judgment of any indemnified party a
conflict of interest may exist between such indemnified party and any other
of such indemnified parties with respect to such claim. Failure to give
prompt written notice shall not release the indemnifying party from its
obligations hereunder.

          (d) To the extent permitted by law, the indemnification provided
for under this Agreement shall remain in full force and effect regardless
of any investigation made by or on behalf of the indemnified party or any
officer, director or controlling person of such indemnified party and shall
survive the transfer of securities.

          (e) If the indemnification provided for in or pursuant to this
Section 7 is due in accordance with the terms thereof, but is for any
reason unavailable or unenforceable or insufficient in respect of any
losses, claims, damages, liabilities or expenses referred to therein, then
each applicable indemnifying party, in lieu of indemnifying such
indemnified party, shall contribute to the amount paid or payable by such
indemnified person as a result of such losses, claims, damages, liabilities
or expenses in such proportion as is appropriate to reflect the relative
fault of the indemnifying party on the one hand and of the indemnified
party on the other in connection with the statements or omissions which
resulted in such losses, claims, damages, liabilities or expenses as well
as any other relevant equitable considerations. The relative fault of the
indemnifying party on the one hand and of the indemnified person on the
other shall be determined by reference to, among other things, whether the
untrue or alleged untrue statement of a material fact or the omission or
alleged omission to state a material fact relates to information supplied
by the indemnifying party or by the indemnified party, by such party's
relative intent, knowledge, access to information and opportunity to
correct or prevent such statement, or omission. In no event shall the
liability of any selling holder of Warrant Shares be greater in amount than
the amount of proceeds received by such holder upon such sale.

          8. Participation in Underwritten Registrations. No Lender may
participate in any registration hereunder which is underwritten unless such
Lender (a) agrees to sell such Lender's securities on the basis provided in
any underwriting arrangements approved by the Person or Persons entitled
hereunder to approve such arrangements and (b) completes and executes all
questionnaires, powers of attorney, indemnities, underwriting agreements
and other documents required under the terms of such underwriting
arrangements.

          9. Miscellaneous. (a) Except as otherwise provided herein, the
provisions of this Agreement may be amended only with the written consent
of the Company and the holders of 66-2/3% of the Warrant Shares.

          (b) All covenants and agreements in this Agreement by or on
behalf of any of the parties hereto shall bind and inure to the benefit of
their respective successors and assigns whether so expressed or not. Each
successor and assign shall agree to be bound by the terms hereof as if
originally a party hereto. In addition, whether or not any express
assignment has been made, the provisions of this Agreement which are for
the benefit of purchasers or holders of the Warrant Shares are also for the
benefit of, and enforceable by, any subsequent holder of such Warrant
Shares, provided that each such transferee shall agree in writing to be
bound by the terms and conditions of this Agreement.

          (c) Whenever possible, each provision of this Agreement shall be
interpreted in such manner as to be effective and valid under applicable
law, but if any provision of this Agreement is held to be prohibited by or
invalid under applicable law, such provision will be ineffective only to
the extent of such prohibition or invalidity, without invalidating the
remainder of such provision or this Agreement.

          (d) This Agreement may be executed simultaneously in two or more
counterparts, each of which shall constitute an original, but all of which
taken together shall constitute one and the same Agreement.

          (e) The headings of this Agreement are inserted for convenience
only and do not constitute a part of this Agreement.

          (f) This Agreement shall be governed by the law of the State of
New York.

          (g) All notices provided for herein shall be given or made by
certified mail or hand delivery, mailed or delivered to the intended
recipient at the "Address of Notices" specified below its name on the
signature pages hereof; or as to any party, at such other address as shall
be designated by such party in a notice to each other party. Except as
otherwise provided in this Agreement, all such communications shall be
deemed to have been duly given when mailed or personally delivered.

          (h) The Company will not hereafter enter into any agreement with
respect to its securities which is inconsistent with the rights granted
under this Agreement to the holders of Warrant Shares.

          (i) Any person having rights under any provisions of this
Agreement will be entitled to enforce such rights specifically, to recover
damages caused by reason of any breach of any provision of this Agreement
and to exercise all other rights granted by law.

          (j) In any action or proceeding brought to enforce any provision
of this Agreement, or where any provision of such Agreement is validly
asserted as a defense, the successfuly party shall receive attorneys fees
in addition to any other available remedy.

<PAGE>

          IN WITNESS WHEREOF, the parties have executed this Agreement as
of the date first written above.

                                GCA CORPORATION

                                By
                                  ------------------------------------
                                7 Shattuck Road
                                Andover, Massachusetts 01810
                                Attention:  General Counsel


                                THE BANK OF NEW ENGLAND, N.A.

                                By
                                  ------------------------------------
                                28 State Street
                                Boston, Massachusetts  02109
                                Attn:  Cynthia Sackett
                                Assistant Vice President


                                BARCLAYS BANK PLC (formerly known as
                                "Barclays Bank International Limited")

                                By
                                  ------------------------------------
                                420 Lexington Avenue
                                New York, New York
                                Attn:  Advance Department


                                MANUFACTURERS HANOVER TRUST COMPANY

                                By
                                  ------------------------------------
                                270 Park Avenue
                                New York, New York  10017
                                Attn:  Gregory Harbaugh
                                Assistant Secretary


                                MANUFACTURERS HANOVER LEASING CORPORATION

                                By
                                  ------------------------------------
                                270 Park Avenue, 29th Floor
                                New York, New York  10017
                                Attn:  Robert Michael
                                Vice President


                                MELLON BANK, N.A.

                                By
                                  ------------------------------------
                                One Mellon Bank Center, Room 4321
                                Pittsburgh, Pennsylvania  15258
                                Attn:  Robert W. Goode
                                Senior Vice President


                                TEACHERS INSURANCE AND ANNUITY
                                ASSOCIATION OF AMERICA

                                By
                                  ------------------------------------
                                730 Third Avenue
                                New York, New York  10017
                                Attn:  Securities Division


                                GENERAL AMERICAN LIFE INSURANCE COMPANY

                                By
                                  ------------------------------------
                                P.O. Box 396
                                St. Louis, Missouri  63166


                                HOME LIFE INSURANCE COMPANY

                                By
                                  ------------------------------------
                                253 Broadway
                                New York, New York  10007
                                Attn:  Securities Department


                                THE PENN MUTUAL LIFE INSURANCE COMPANY

                                By
                                  ------------------------------------
                                530 Walnut Street
                                Philadelphia, Pennsylvania  19172
                                Attn:  Securities Department


                                THE UNION CENTRAL LIFE INSURANCE COMPANY

                                By
                                  ------------------------------------
                                P.O. Box 179
                                Cincinnati, Ohio  45201


                                THE UNION LABOR LIFE INSURANCE COMPANY

                                By
                                  ------------------------------------
                                111 Massachusetts Ave., N.W.
                                Washington, D.C.  20001
                                Attn:  Barbara Riley


                                PAN AMERICAN LIFE INSURANCE COMPANY

                                By
                                  ------------------------------------
                                601 Poybras Street
                                Pan American Life Center
                                New Orleans, Louisiana  70130
                                Attn:  28th Floor Investments


                                BERKSHIRE LIFE INSURANCE COMPANY

                                By
                                  ------------------------------------
                                700 South Street
                                Pittsfield, Massachusetts  01201
                                Attn:  Securities Department