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                                                                   EXHIBIT 10(d)


                          REGISTRATION RIGHTS AGREEMENT
                          -----------------------------

                  THIS AGREEMENT is made as of December 31, 1996, by and among
Core Materials Corporation, a Delaware corporation (the "COMPANY"), Navistar
International Transportation Corp., a Delaware corporation ("Navistar") and each
of the other Persons who becomes a party to this Agreement after the date hereof
pursuant to paragraphs 10(e) or 10(f) below. Certain capitalized terms used
herein are defined in paragraph 9 below.

                  WHEREAS, RYMAC Mortgage Investment Corporation ("RYMAC") and
Navistar are parties to an Asset Purchase Agreement dated as of September 12,
1996, as amended (the "PURCHASE AGREEMENT") pursuant to which Navistar has
agreed to sell certain assets to the Company (as successor to RYMAC) subject to
the terms and conditions therein.

                  WHEREAS, as part of the consideration for the sale of certain
of its assets, the Company is issuing to Navistar certain shares of the
Company's Common Stock, par value $.01 per share (the "COMMON STOCK"); and

                  WHEREAS, the execution and delivery of this Agreement is a
condition to Navistar's obligation to sell certain assets to the Company
pursuant to the Purchase Agreement.

                  NOW, THEREFORE, in consideration of the mutual covenants
contained herein and other good and valuable consideration, the receipt and
sufficiency of which are hereby acknowledged, the parties to this Agreement
intending to be legally bound, hereby agree as follows:

                  The parties hereto agree as follows:

                  1.  DEMAND REGISTRATIONS.

                  (a) REQUESTS FOR REGISTRATION. The holders of at least 20% of
the Investor Registrable Securities may at any time request registration under
the Securities Act of all or any portion of their Registrable Securities on Form
S-1 or any similar long-form registration ("LONG-FORM REGISTRATIONS"), and the
holders of at least 20% of the Investor Registrable Securities may request
registration under the Securities Act of 1933, as amended (the "SECURITIES ACT")
of all or any portion of their Registrable Securities on Form S-2 or S-3
(including pursuant to Rule 415 under the Securities Act) or any similar
short-form registration ("SHORT-FORM REGISTRATIONS") if available. All
registrations requested pursuant to this paragraph 1(a) are referred to herein
as "DEMAND REGISTRATIONS". Each request for a Demand Registration shall specify
the approximate number of Investor Registrable Securities requested to be
registered and the anticipated per share price range for such offering. Within
10 days after receipt of any such request, the Company shall give written notice
of such requested registration to all other holders of Registrable Securities
and shall include in such registration all Registrable Securities with respect
to which the Company has received written requests for inclusion therein within
15 days after the receipt of the Company's notice.


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                  (b) LONG-FORM REGISTRATIONS. The holders of Investor
Registrable Securities shall be entitled to request 2 Long-Form Registrations.
The Company shall pay all Registration Expenses for such Long-Form
Registrations. Except as otherwise provided in this paragraph 1(b), (i) a
registration shall not count as one of the permitted Long-Form Registrations
until it has become effective and the holders of Investor Registrable Securities
are able to register and sell at least 90% of the Investor Registrable
Securities requested to be included in such registration; and (ii) the Company
shall pay all Registration Expenses in connection with any registration
initiated as a Long-Form Registration whether or not it has become effective and
whether or not such registration has counted as one of the permitted Long-Form
Registrations. The holders of Investor Registrable Securities may, before a
Long-Form Registration becomes effective, withdraw their Registrable Securities
from inclusion therein, should the terms of sale not be satisfactory to such
holders. Should all such holders so withdraw, such Long-Form Registration shall
be deemed to have been declared effective, unless such holders of Investor
Registrable Securities pay within 30 days after any such withdrawal, their
pro-rata share of all of the out-of-pocket expenses of the Company incurred in
connection with such registration.

                  If so requested by the holders of at least a majority of the
Investor Registrable Securities included in a Demand Registration, the public
offering or distribution of Registrable Securities under this Agreement shall be
pursuant to a firm commitment underwriting, the managing underwriter of which
shall be a nationally recognized investment banking firm selected and engaged by
the Company and approved by the holders of at least a majority of the Investor
Registrable Securities included in such Demand Registration (which approval
shall not be unreasonably withheld). The Company shall enter into the same
underwriting agreement as entered into by the holders of Investor Registrable
Securities, which shall contain representations, warranties, indemnities and
agreements not substantially different from those customarily made by an issuer
in underwriting agreements with respect to secondary distributions. The Company,
as a condition to fulfilling its obligations under this Agreement, may require
that such underwriting agreement contain customary provisions indemnifying the
Company against any losses that arise out of or are based upon an untrue
statement, an alleged untrue statement, an omission or an alleged omission in
any registration statement or prospectus made in reliance upon and in conformity
with written information furnished to the Company by the underwriters
specifically for use in the preparation of such registration statement or
prospectus.

                  (c) SHORT-FORM REGISTRATIONS. In addition to the Long-Form
Registrations provided pursuant to paragraph 1(b), the holders of Investor
Registrable Securities shall be entitled to request an unlimited number of
Short-Form Registrations in which the Company shall pay all Registration
Expenses. Demand Registrations shall be Short-Form Registrations whenever the
Company is permitted to use any applicable short form. The Company shall use its
best efforts to make Short-Form Registrations on Form S-3 available for the sale
of Registrable Securities. If the Company, pursuant to the request of the
holders of at least 20% of the Investor Registrable Securities, is qualified to
and has filed with the Securities and Exchange Commission a registration
statement under the Securities Act on Form S-3 pursuant to Rule 415 under the
Securities Act (the "REQUIRED REGISTRATION"), the Company shall use its best
efforts to cause the Required Registration to be declared effective under the
Securities Act as soon as practical after



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filing, and once effective, the Company shall cause such Required Registration
to remain effective for a period ending on the earlier of (i) the date on which
all Registrable Securities have been sold pursuant to the Required Registration
or (ii) the date as of which the holders of Investor Registrable Securities
(assuming such holders are affiliates of the Company) are able to sell all of
the Investor Registrable Securities then held by them within a ninety-day period
in compliance with Rule 144 under the Securities Act (the "EFFECTIVE PERIOD").
The Company represents, warrants and covenants that it currently is, and shall
remain at all times during the Effective Period, eligible to use Form S-2 under
the Securities Act. Each party hereto hereby acknowledges that the Company is
currently not eligible to effect a Required Registration for a primary offering,
but is eligible to effect a Required Registration for a secondary offering.

                  (d) PRIORITY ON DEMAND REGISTRATIONS. The Company shall not
include in any Demand Registration any securities which are not Registrable
Securities without the prior written consent of the holders of at least 50% of
the Investor Registrable Securities included in such registration. If a Demand
Registration is an underwritten offering and the managing underwriter advises
the Company in writing that in its opinion the number of Registrable Securities
and, if permitted hereunder, other securities requested to be included in such
offering exceeds the number of Registrable Securities and other securities, if
any, which can be sold without adversely affecting the marketability of the
offering, the Company shall include in such registration prior to the inclusion
of any securities which are not Registrable Securities the number of Registrable
Securities requested to be included which in the opinion of such underwriters
can be sold without adversely affecting the marketability of the offering, first
pro rata among the respective holders of the Investor Registrable Securities and
then to the extent that any Other Registrable Securities can still be included,
pro rata among the respective holders thereof on the basis of the amount of
Registrable Securities owned by each such holder, and then to the extent that
any securities which are not Registrable Securities can still be included, pro
rata among the respective holders thereof on the basis of the amount of such
securities owned by each such holder. Any Persons other than holders of
Registrable Securities who participate in Demand Registrations which are not at
the Company's expense must pay their share of the Registration Expenses as
provided in paragraph 5 hereof.

                  (e) RESTRICTIONS ON DEMAND REGISTRATIONS. The Company shall
not be obligated to effect any Demand Registration within 180 days after the
effective date of a previous Demand Registration or a previous registration in
which the holders of Registrable Securities were given piggyback rights pursuant
to Section 2 and in which there was no reduction in the number of Registrable
Securities requested to be included. The Company shall be entitled to postpone,
for a reasonable period of time not in excess of 90 days after its receipt of an
initial request for a Demand Registration pursuant to this Agreement, the filing
of any registration statement if at the time it received a request therefor, the
Company determines, in its reasonable business judgment, that such registration
and offering could interfere with or otherwise adversely affect any financing,
acquisition, corporate reorganization or other material transaction or
development involving the Company or any of its subsidiaries or affiliates;
provided that the Company shall only be entitled to one postponement in any
365-day period. The Company shall give the holders of Investor Registrable
Securities making such request written notice of such determination. In the
event of such postponement, the Company shall file such Registration

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Statement as soon as practicable after it shall determine, in its reasonable
business judgment, that such registration and offering will not interfere with
the matters described in the first sentence of this Section 2(e) or, if later,
at the end of such 90-day period. If the Company shall postpone the filing of
any registration statement, the holders of Investor Registrable Securities shall
have the right to withdraw their request for such registration by giving notice
to the Company within 15 days of the notice of postponement; provided, however,
that in the event that the holders of Investor Registrable Securities withdraw
their request in the foregoing manner, such request shall not be counted for
purposes of determining the number of registrations to which the holders of
Investor Registrable Securities are entitled pursuant to paragraph (a) above.

                  Notwithstanding the provisions of this paragraph 1, the
Company shall not be required to effect more than two Long-Form Registrations or
more than five Demand Registrations that have been filed pursuant to paragraph
1(a) above, were declared effective by the Commission and remained effective for
the period set forth in paragraph 4(b) hereof.

                  (f) OTHER REGISTRATION RIGHTS. Except as provided in this
Agreement, the Company shall not grant to any Persons the right to request the
Company to register any equity securities of the Company, or any securities
convertible or exchangeable into or exercisable for such securities, without the
prior written consent of the holders of at least 50% of the Investor Registrable
Securities; provided that the Company may grant rights to employees of the
Company and its Subsidiaries to participate in Piggyback Registrations so long
as such rights are subordinate to the rights of the holders of Registrable
Securities with respect to such Piggyback Registrations as provided in
paragraphs 2(c) and 2(d) below.

                  2. PIGGYBACK REGISTRATIONS.

                  (a) RIGHT TO PIGGYBACK. Whenever the Company proposes to
register any of its 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 Registrable Securities (a "PIGGYBACK REGISTRATION"), the Company
shall give prompt written notice to all holders of Registrable Securities of its
intention to effect such a registration and shall include in such registration
all Registrable Securities with respect to which the Company has received
written requests for inclusion therein within 15 days after the receipt of the
Company's notice.

                  (b) PIGGYBACK EXPENSES. The Registration Expenses of the
holders of Registrable Securities shall be paid by the Company in all Piggyback
Registrations.

                  (c) PRIORITY ON PIGGYBACK REGISTRATIONS. 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
opinion the number of securities requested to be included in such registration
exceeds the number which can be sold without adversely affecting the
marketability of the offering, the Company shall include in such registration
(i) first, the securities the Company proposes to sell, (ii) second, the
Investor Registrable Securities requested to be included in such registration,
pro rata among the holders of such Investor Registrable Securities on the basis
of the number of shares owned by each such holder, (iii) third, the Other


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Registrable Securities requested to be included in such registration,
pro rata among the holders of such Registrable Securities on the basis of the
number of shares owned by each such holder, and (iv) fourth, other securities
requested to be included in such registration pro rata among the holders of
such securities on the basis of the number of shares owned by each such holder.

                  (d) PRIORITY ON SECONDARY REGISTRATIONS. If a Piggyback
Registration is an underwritten secondary registration on behalf of holders of
the Company's securities, and the managing underwriters advise the Company in
writing that in their opinion the number of securities requested to be included
in such registration exceeds the number which can be sold without adversely
affecting the marketability of the offering, 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 Investor Registrable
Securities requested to be included in such registration, pro rata among the
holders of such Investor Registrable Securities on the basis of the number of
shares owned by each such holder, (iii) third, the Other Registrable Securities
requested to be included in such registration, pro rata among the holders of
such Registrable Securities on the basis of the number of shares owned by each
such holder, and (iv) fourth, other securities requested to be included in such
registration pro rata among the holders of such securities on the basis of the
number of shares owned by each such holder.

                  (e) SELECTION OF UNDERWRITERS. If any Piggyback Registration
is an underwritten offering, the selection of investment banker(s) and
manager(s) for the offering must be approved by the holders of a majority of the
Investor Registrable Securities included in such Piggyback Registration. Such
approval shall not be unreasonably withheld or delayed.

                  (f) OTHER REGISTRATIONS. If the Company has previously filed a
registration statement with respect to Registrable Securities pursuant to
paragraph l or pursuant to this paragraph 2, and if such previous registration
has not been withdrawn or abandoned, the Company shall not file or cause to be
effected any other registration of any of its equity securities or securities
convertible or exchangeable into or exercisable for its equity securities under
the Securities Act (except on Form S-8 or any successor form), whether on its
own behalf or at the request of any holder or holders of such securities, until
a period of at least 180 days has elapsed from the effective date of such
previous registration.

                  3. HOLDBACK AGREEMENTS.

                  (a) Each holder of Registrable Securities shall not effect any
public sale or distribution (including sales pursuant to Rule 144) of equity
securities of the Company, or any securities convertible into or exchangeable or
exercisable for such securities, during the 10 days prior to and the 180-day
period beginning on the effective date of any underwritten Demand Registration
or any underwritten Piggyback Investor Registration in which Registrable
Securities are included (except as part of such underwritten registration),
unless the underwriters managing the registered public offering otherwise agree.

                  (b) The Company (i) shall not effect any public sale or
distribution of its equity securities,


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or any securities convertible into or exchangeable or exercisable for such
securities, during the ten days prior to and during the 180-day period beginning
on the effective date of any (x) underwritten Demand Registration, (y)
underwritten Piggyback Registration (except as part of such underwritten
registration or pursuant to registrations on Form S-8 or any successor form) or
(z) post-effective amendment of a Required Registration pursuant to which an
underwritten offering is to be effected, unless (in any such case) the
underwriter managing the registered public offering otherwise agrees.

                  4. REGISTRATION PROCEDURES. Whenever the holders of
Registrable Securities have requested that any Registrable Securities be
registered pursuant to this Agreement, the Company shall use its best efforts to
effect the registration and the sale of such Registrable Securities 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 Registrable Securities
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 shall furnish to the counsel
selected by the holders of a majority of the Investor Registrable Securities
covered by such registration statement copies of all such documents proposed to
be filed, which documents shall be subject to the reasonable review and comment
of such counsel);

                  (b) notify each holder of Registrable Securities of the
effectiveness of each registration statement filed hereunder and 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 180 days or such longer period specified in paragraph 1(c) 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 Registrable Securities 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 Registrable Securities
owned by such seller;

                  (d) use its best efforts to register or qualify such
Registrable Securities 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 Registrable
Securities owned by such seller (provided that the Company shall 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, (ii) subject itself
to taxation in any such jurisdiction or (iii) consent to general service of
process in any such jurisdiction);


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                  (e) notify each seller of such Registrable Securities, at any
time when a prospectus relating thereto is required to be delivered under the
Securities Act, of the happening 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, at the request of any such seller, the Company shall
prepare a supplement or amendment to such prospectus so that, as thereafter
delivered to the purchasers of such Registrable Securities, 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) cause all such Registrable Securities to be listed on each
securities exchange on which similar securities issued by the Company are then
listed;

                  (g) provide a transfer agent and registrar for all such
Registrable Securities and a CUSIP number for all such Registrable Securities
not later than the effective date of such registration statement;

                  (h) 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 Registrable Securities being sold or the
underwriters, if any, reasonably request in order to expedite or facilitate the
disposition of such Registrable Securities (including effecting a stock split or
a combination of shares);

                  (i) make available for inspection by any seller of Registrable
Securities, 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, subject to
the execution by any such person of a confidentiality agreement in form and
substance reasonably satisfactory to the Company;

                  (j) otherwise use its best efforts to comply with all
applicable rules and regulations of the Securities and Exchange Commission, and
make available to its security holders, as soon as reasonably practicable, an
earnings statement covering the period of at least twelve months beginning with
the first day of the Company's first full calendar quarter after the effective
date of the registration statement, which earnings statement shall satisfy the
provisions of Section 11(a) of the Securities Act and Rule 158 thereunder;

                  (k) permit any holder of Registrable Securities which holder,
in its sole and exclusive judgment, might be deemed to be an underwriter or a
controlling person of the Company, to participate in the preparation of such
registration or comparable statement and to require the insertion therein of
material, furnished to the Company in writing, which in the reasonable judgment
of such holder and its counsel should be included;


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                  (l) in the event of the issuance of any stop order suspending
the effectiveness of a registration statement, or of any order suspending or
preventing the use of any related prospectus or suspending the qualification of
any common stock included in such registration statement for sale in any
jurisdiction, use its best efforts promptly to obtain the withdrawal of such
order;

                  (m) use its best efforts to cause such Registrable Securities
covered by such registration statement to be registered with or approved by such
other governmental agencies or authorities as may be necessary to enable the
sellers thereof to consummate the disposition of such Registrable Securities;

                  (n) obtain a cold comfort letter from the Company's
independent public accountants in customary form and covering such matters of
the type customarily covered by cold comfort letters as the holders of a
majority of the Investor Registrable Securities being sold reasonably request
(provided that such Investor Registrable Securities constitute at least 10% of
the securities covered by such registration statement); and

                  (o) use reasonable efforts to cause certificates for the
Registrable Securities covered by such registration statement to be delivered by
the holders thereof to the underwriters in such denominations and registered in
such names as the underwriters may request.

                  5. REGISTRATION EXPENSES.

                  (a) Subject to paragraph (b) below, all expenses incident to
the Company's performance of or compliance with this Agreement, including
without limitation all registration and filing fees, fees and expenses of
compliance with securities or blue sky laws, printing expenses, messenger and
delivery expenses, fees and disbursements of custodians, fees and disbursements
of counsel for the Company and fees and disbursements of all independent
certified public accountants, underwriters (excluding discounts and commissions)
and other Persons retained by the Company or the holders of Investor Registrable
Securities (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 or on the NASD automated
quotation system.

                  (b) In connection with each Demand Registration and each
Piggyback Registration, the Company shall reimburse the holders of Registrable
Securities included in such registration for the reasonable fees and
disbursements of one counsel chosen by the holders of a majority of the Investor
Registrable Securities included in such registration and for the reasonable fees
and disbursements of each additional counsel retained by any holder of
Registrable Securities for the purpose of rendering a legal opinion on behalf of
such holder in connection with any underwritten Demand Registration or Piggyback
Registration.


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                  (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 those 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.

                  6. INDEMNIFICATION.

                  (a) The Company agrees to indemnify, to the extent permitted
by law, each holder of Registrable Securities, its officers, directors and
partners, legal counsel, accountants and each Person who controls such holder
(within the meaning of the Securities Act) against all losses, claims, damages,
liabilities and expenses (including investigation costs and costs of defending
same) caused by (i) 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 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 or any violation of federal or state securities laws, rules or
regulations relating to actions or inactions required by such holder, its
officers, directors or partners or any Person who controls such holder (within
the meaning of the Securities Act) in connection with any such registration or
qualification or (ii) any violation by the Company of the Securities Act or any
regulation thereunder applicable to the Company and relating to action or
inaction required of the Company in connection with any such registration,
qualification or compliance. 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 Registrable Securities.

                  (b) In connection with any registration statement in which a
holder of Registrable Securities 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 the Company,
officers, directors and partners, and each Person who controls the Company
(within the meaning of the Securities Act) against any losses, claims, damages,
liabilities and expenses (including investigations and cost of defending same)
resulting from 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 and stated to be specifically for use therein; provided that the
obligation to indemnify shall be individual, not joint and several, for


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each holder and shall be limited to the net amount of proceeds received by such
holder from the sale of Registrable Securities 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 (provided that the failure to give prompt
notice shall not impair any Person's right to indemnification hereunder to the
extent such failure has not prejudiced the indemnifying party) 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 shall 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.

                  (d) 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, legal counsel,
accountant, partner or controlling Person of such indemnified party and shall
survive the transfer of securities. The Company also agrees to make such
provisions, as are reasonably requested by any indemnified party, for
contribution to such party in the event the Company's indemnification is
unavailable for any reason.

                  (e) If the indemnification provided for in this paragraph 6 is
held by a court of competent jurisdiction to be unavailable to an indemnified
party with respect to any loss, liability, claim, damage, or expense referred to
therein, then the indemnifying party, in lieu of indemnifying such indemnified
party hereunder, shall contribute to the amount paid or payable by such
indemnified party as a result of such loss, liability, claim, damage, or expense
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 that resulted in such loss,
liability, claim, damage, or expense as well as any other relevant equitable
considerations. The relative fault of the indemnifying party and of the
indemnified party shall be determined by reference to, among other things,
whether the untrue or alleged untrue statement of a material fact or the
omission to state a material fact relates to information supplied by the
indemnifying party or by the indemnified party and the parties' relative intent,
knowledge, access to information, and opportunity to correct or prevent such
statement or omission.

                  (f) Notwithstanding the foregoing, to the extent that the
provisions on indemnification and contribution contained in the underwriting
agreement entered into in connection with the underwritten public offering are
in conflict with the foregoing provisions, the provisions in the underwriting
agreement shall control.


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                  7. PARTICIPATION IN UNDERWRITTEN REGISTRATIONS. No Person may
participate in any registration hereunder which is underwritten unless such
Person (i) agrees to sell such Person's securities on the basis provided in any
underwriting arrangements approved by the Person or Persons entitled hereunder
to approve such arrangements and (ii) completes and executes all questionnaires,
powers of attorney, indemnities, underwriting agreements and other documents
required under the terms of such underwriting arrangements; provided that no
holder of Investor Registrable Securities included in any underwritten
registration shall be required to make any representations or warranties to the
Company or the underwriters (other than representations and warranties regarding
such holder and such holder's intended method of distribution) or to undertake
any indemnification obligations to the Company or the underwriters with respect
thereto, except as otherwise provided in paragraph 6 hereof. The Company's
obligations under this Agreement with respect to each seller of Registrable
Securities shall be conditioned upon such seller's compliance with the
following:

                  (a) Such seller shall cooperate with the Company in connection
with the preparation of the registration statement, and for so long as the
Company is obligated to keep the registration statement effective, shall provide
to the Company, in writing, for use in the registration statement, all
information reasonably requested by the Company regarding such seller and such
other information relating to such seller as may be necessary to enable the
Company to prepare the registration statement and prospectus covering the
Registrable Securities, to maintain the currency and effectiveness thereof, and
to otherwise comply with all applicable requirements of law in connection
therewith;

                  (b) during such time as such seller may be engaged in a
distribution of Registrable Securities, such seller will comply with all
applicable laws including but not limited to Rules 10b-6 and 10b-7 promulgated
under the Securities Exchange Act of 1934, as amended (the "EXCHANGE ACT") and
pursuant thereto will, among other thing: (A) not engage in any stabilization
activity in connection with the securities of the Company in contravention of
such rules; (B) distribute the Registrable Securities owned by such seller
solely in the manner described in the registration statement; (C) cause to be
furnished to each underwriter, agent or broker-dealer to and through whom the
Registrable Securities owned by such seller may be offered, or to the offeree if
an offer is made directly by such seller, such copies of the prospectus (as
amended and supplemented to such date) and documents incorporated by reference
therein as may be required by such underwriter, agent, broker-dealer or offeree;
and (D) not bid for or purchase any securities of the Company or attempt to
induce any person to purchase any securities of the Company other than as
permitted under the Exchange Act; and

                  (c) on notice from the Company of the happening of any of the
events specified in paragraph 4(e) above, if it requires the suspension by such
seller of the distribution of any of the Registrable Securities, then such
seller shall cease offering or distributing the Registrable Securities until
such time as the Company notifies such seller that offering and distribution of
the Registrable Securities may recommence (which in any event shall be no later
than immediately after the filing of the supplemented or amended prospectus
contemplated by Section 4(e)).


                                      -66-
<PAGE>

                  8. RULE 144 REPORTING. With a view to making available the
benefits of certain rules and regulations of the Securities and Exchange
Commission that may permit the sale of Registrable Securities to the public
without registration, the Company agrees to use its best efforts to:

                  (a) make and keep public information regarding the Company
available as those terms are understood and defined in Rule 144 under the
Securities Act;

                  (b) file with the Securities and Exchange Commission in a
timely manner all reports and other documents required of the Company under the
Securities Act and the Securities Exchange Act of 1934, as amended (the
"EXCHANGE ACT") at any time after it has become subject to such reporting
requirements; and

                  (c) so long as a holder owns any Registrable Securities,
furnish to the holder forthwith upon written request a written statement by the
Company as to its compliance with the reporting requirements of Rule 144, and of
the Securities Act and the Exchange Act, a copy of the most recent annual or
quarterly report of the Company, and such other reports and documents so filed
as a holder may reasonably request in availing itself of any rule or regulation
of the Securities and Exchange Commission allowing a holder to sell any such
securities without registration.

                  9. DEFINITIONS.

                  "INVESTOR REGISTRABLE SECURITIES" means any shares of Common
Stock held by Navistar and its affiliates and any other shares of Common Stock
held by a person who is a party to this Agreement and are designated as such by
Navistar.

                  "OTHER REGISTRABLE SECURITIES" means any shares of Common
Stock held by a person who is a party to this Agreement that do not constitute
Investor Registrable Securities.

                  "REGISTRABLE SECURITIES" means Investor Registrable Securities
and Other Registrable Securities. As to any particular Registrable Securities,
such securities shall cease to be Investor or Other Registrable Securities when
they have been distributed to the public pursuant to an offering registered
under the Securities Act or sold to the public through a broker, dealer or
market maker in compliance with Rule 144 under the Securities Act (or any
similar rule then in force). For purposes of this Agreement, a Person shall be
deemed to be a holder of Registrable Securities whenever such Person has the
right to acquire such Registrable Securities (upon conversion or exercise in
connection with a transfer of securities or otherwise, but disregarding any
restrictions or limitations upon the exercise of such right), whether or not
such acquisition has actually been effected, and such Person shall be entitled
to exercise the rights of a holder of Registrable Securities hereunder.

                  "SUBSIDIARY" means, with respect to any Person, any
corporation, partnership, association or other business entity of which (i) if a
corporation, a majority of the total voting power of shares of stock entitled
(without regard to the occurrence of any contingency) to vote in


                                      -67-
<PAGE>

the election of directors, managers or trustees thereof is at the time owned or
controlled, directly or indirectly, by that Person or one or more of the other
Subsidiaries of that Person or a combination thereof, or (ii) if a partnership,
association or other business entity, a majority of the partnership or other
similar ownership interest thereof is at the time owned or controlled, directly
or indirectly, by any Person or one or more Subsidiaries of that Person or a
combination thereof. For purposes hereof, a Person or Persons shall be deemed to
have a majority ownership interest in a partnership, association or other
business entity if such Person or Persons shall be allocated a majority of
partnership, association or other business entity gains or losses or shall be or
control any managing director or general partner of such partnership,
association or other business entity. For purposes hereof, reference to a
"Subsidiary" of the Company shall be given effect only at such times as the
Company has one or more Subsidiaries.

                  10.  MISCELLANEOUS.

                  (a) NO INCONSISTENT AGREEMENTS. The Company shall not
hereafter enter into any agreement with respect to its securities which is
inconsistent with or violates the rights granted to the holders of Registrable
Securities in this Agreement.

                  (b) ADJUSTMENTS AFFECTING REGISTRABLE SECURITIES. The Company
shall not take any action, or permit any change to occur, with respect to its
securities which would adversely affect the ability of the holders of
Registrable Securities to include such Registrable Securities in a registration
undertaken pursuant to this Agreement or which would adversely affect the
marketability of such Registrable Securities in any such registration
(including, without limitation, effecting a stock split or a combination of
shares).

                  (c) REMEDIES. Any Person having rights under any provision of
this Agreement shall 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. The parties hereto agree and
acknowledge that money damages may not be an adequate remedy for any breach of
the provisions of this Agreement and that any party may in its sole discretion
apply to any court of law or equity of competent jurisdiction (without posting
any bond or other security) for specific performance and for other injunctive
relief in order to enforce or prevent violation of the provisions of this
Agreement.

                  (d) AMENDMENTS AND WAIVERS. Except as otherwise provided
herein, no modification, amendment or waiver of any provision of this Agreement
shall be effective against the Company or the holders of Registrable Securities
unless such modification, amendment or waiver is approved in writing by the
Company and the holders of at least a majority of the Registrable Securities
then in existence, which majority shall include a majority of the Investor
Registrable Securities then in existence; provided that no such amendment or
action which materially adversely affects any one holder of Registrable
Securities, as such, vis-a-vis the other holders of Registrable Securities, as
such, shall be effective against such holder without the prior written consent
of such holder. The failure of any party to enforce any of the provisions of
this Agreement shall in no way be construed as a waiver of such provisions and
shall not affect the


                                      -68-
<PAGE>


right of such party thereafter to enforce each and every provision of this
Agreement in accordance with its terms.

                  (e) ADDITIONAL PARTIES. The Board of Directors of the Company
shall be entitled, but not obligated, to allow any purchaser of Common Stock (or
securities or rights convertible or exercisable into Common Stock) to execute a
counterpart to this Agreement and become a party hereto (each, an "ADDITIONAL
PARTY"), in which case the Common Stock issued or issuable to any such
Additional Party shall be deemed "Registrable Securities" for purposes of this
Agreement. Except as set forth in this paragraph 10(e) and in paragraph 1(g),
the Company will not grant to any other Persons any registration rights.

                  (f) SUCCESSORS AND ASSIGNS. 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 the respective successors and assigns of the parties hereto
whether so expressed or not. In addition, whether or not any express assignment
has been made, the provisions of this Agreement which are for the benefit of the
purchasers or holders of Registrable Securities are also for the benefit of, and
enforceable by, any subsequent holder of Registrable Securities. Notwithstanding
the foregoing, (a) in order to obtain the benefit of this Agreement, any
subsequent holder of Registrable Securities must execute a counterpart to this
Agreement, thereby agreeing to be bound the terms hereof and (b) the right to
designate "Investor Registrable Securities" is not assignable unless the person
holding such right explicitly assigns such right to the assignee or transferee
of all or a portion of its Registrable Securities.

                  (g) SEVERABILITY. 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 shall be ineffective only to
the extent of such prohibition or invalidity, without invalidating the remainder
of this Agreement.

                  (h) COUNTERPARTS. This Agreement may be executed
simultaneously in two or more counterparts, any one of which need not contain
the signatures of more than one party, but all such counterparts taken together
shall constitute one and the same Agreement.

                  (i) DESCRIPTIVE HEADINGS. The descriptive headings of this
Agreement are inserted for convenience only and do not constitute a part of this
Agreement.

                  (j) GOVERNING LAW. The corporate law of the State of Delaware
shall govern all issues and questions concerning the relative rights of the
Company and its stockholders. All other issues and questions concerning the
construction, validity, interpretation and enforcement of this Agreement and the
exhibits and schedules hereto shall be governed by, and construed in accordance
with, the laws of the State of Ohio, without giving effect to any choice of law
or conflict of law rules or provisions (whether of the State of Ohio or any
other jurisdiction) that would cause the application of the laws of any
jurisdiction other than the State of Ohio. In furtherance of the foregoing, the
internal law of the State of Ohio shall control the interpretation and
construction of this Agreement (and all schedules and exhibits hereto), even
though under


                                      -69-
<PAGE>

that jurisdiction's choice of law or conflict of law analysis, the substantive
law of some other jurisdiction would ordinarily apply.

                  (k) NOTICES. All notices, demands or other communications to
be given or delivered under or by reason of the provisions of this Agreement
shall be in writing and shall be deemed to have been given when delivered
personally to the recipient, sent to the recipient by reputable overnight
courier service (charges prepaid) or mailed to the recipient by certified or
registered mail, return receipt requested and postage prepaid. Such notices,
demands and other communications shall be sent to holder of Registrable
Securities at the address indicated on the books and records of the Company and
to the Company at its principal executive office (to the attention of the
Company's president) or to such other address or to the attention of such other
person as the recipient party has specified by prior written notice to the
sending party.

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


                           CORE MATERIALS CORPORATION


                           By:  /s/ Richard R. Conte
                                ----------------------------------

                           Its:  President
                                ----------------------------------

                           NAVISTAR INTERNATIONAL TRANSPORTATION CORP.


                           By:  /s/ Thomas M. Hough
                                ----------------------------------

                           Its: Vice President and Treasurer
                                ----------------------------------

                                     -70-