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                                                                    EXHIBIT 4.11

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                         REGISTRATION RIGHTS AGREEMENT


                              Dated May 28, 1997


                                     among


                                NGC CORPORATION

                        NGC CORPORATION CAPITAL TRUST I


                                      and


                             LEHMAN BROTHERS INC.
                             SALOMON BROTHERS INC
                                      and
                               SMITH BARNEY INC.

                             as Initial Purchasers

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                         REGISTRATION RIGHTS AGREEMENT

          THIS REGISTRATION RIGHTS AGREEMENT (this "Agreement") is made and
entered into as of May 28, 1997, among NGC CORPORATION, a Delaware corporation
(the "Company"), NGC CORPORATION CAPITAL TRUST I, a business trust created under
the laws of the State of Delaware (the "Trust"), and LEHMAN BROTHERS INC.,
SALOMON BROTHERS INC and SMITH BARNEY INC. (the "Initial Purchasers").

          This Agreement is made pursuant to the Purchase Agreement, dated 
May 22, 1997 (the "Purchase Agreement"), among the Company, as issuer of the
Series A 8.316% Subordinated Deferrable Interest Debentures due June 1, 2027
(the Subordinated Debentures"), the Trust and the Initial Purchasers, which
provides for, among other things, the sale by the Trust to the Initial
Purchasers of 200,000 of the Trust's Series A 8.316% Subordinated Capital Income
Securities, liquidation amount $1,000 per Capital Security (the "Capital
Securities"), the proceeds of which will be used by the Trust to purchase
Subordinated Debentures. The Capital Securities, together with the Subordinated
Debentures and the Company's guarantee of the Capital Securities (the "Capital
Securities Guarantee"), are collectively referred to as the "Securities". In
order to induce the Initial Purchasers to enter into the Purchase Agreement, the
Company and the Trust have agreed to provide to the Initial Purchasers and its
direct and indirect transferees the registration rights set forth in this
Agreement. The execution and delivery of this Agreement is a condition to the
closing under the Purchase Agreement.

          In consideration of the foregoing, the parties hereto agree as
follows:

          1.   Definitions.  As used in this Agreement, the following
capitalized defined terms shall have the following meanings:

     "Additional Distributions" shall have the meaning set forth in 
Section 2(e)hereof.

     "Advice" shall have the meaning set forth in the last paragraph of 
Section 3 hereof.

     "Applicable Period" shall have the meaning set forth in Section 3(w)
hereof.

     "Business Day" means any day other than a Saturday, a Sunday, or a day on
which banking institutions in Chicago, Illinois or Houston, Texas are authorized
or required by law or executive order to close.

     "Closing Date" shall mean the Closing Date as defined in the Purchase
Agreement.

     "Company" shall have the meaning set forth in the preamble to this
Agreement and also includes the Company's successors and permitted assigns.

     "Consummate" the Exchange Offer shall be deemed "Consummated" for purposes
of this Agreement upon the occurrence of (i) the filing and effectiveness under
the Securities Act of the Exchange Offer Registration Statement relating to the
Exchange Securities to be issued in the 

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Exchange Offer, (ii) the maintenance of such Registration Statement continuously
effective and the keeping of the Exchange Offer open for a period not less than
the minimum period required pursuant to Section 2(a)(iii) hereof, and (iii) the
delivery by the Company and the Trust of the Exchange Securities in the same
aggregate liquidation amount and principal amount as the aggregate liquidation
amount and principal amount, as the case may be, of Securities that were
tendered by Holders thereof pursuant to the Exchange Offer.

     "Declaration" or "Declaration of Trust" shall mean the Amended and Restated
Declaration of Trust, dated as of May 28, 1997, by the trustees named therein
and the Company, as sponsor.

     "Depositary" shall mean The Depository Trust Company, or any other
depositary appointed by the Trust; provided, however, that such depositary must
have an address in the Borough of Manhattan, in The City of New York.

     "Effectiveness Period" shall have the meaning set forth in Section 2(b)
hereof.

     "Exchange Act" shall mean the Securities Exchange Act of 1934, as amended
from time to time.

     "Exchange Offer" shall mean the offer by the Company and the Trust to the
Holders to exchange all of the Registrable Securities (other than Private
Exchange Securities) for a like principal amount of Exchange Securities pursuant
to Section 2(a) hereof.

     "Exchange Offer Registration" shall mean a registration under the
Securities Act effected pursuant to Section 2(a) hereof.

     "Exchange Offer Registration Statement" shall mean an exchange offer
registration statement on Form S-4 (or, if applicable, on another appropriate
form), and all amendments and supplements to such registration statement, in
each case including the Prospectus contained therein, all exhibits thereto and
all material incorporated by reference therein.

     "Exchange Period" shall have the meaning set forth in Section 2(a) hereof.

     "Exchange Securities" shall mean (i) with respect to the Subordinated
Debentures, the Series B 8.316% Subordinated Deferrable Interest Debentures due
June 1, 2027 (the "Exchange Debentures") of the Company containing terms
substantially identical to the Subordinated Debentures (except that they will
not contain terms with respect to the transfer restrictions under the Securities
Act (other than requiring minimum transfers thereof to be in blocks of $100,000
aggregate principal amount), and will not provide for any Liquidated Damages
thereon), (ii) with respect to the Capital Securities, the Trust's Series B
8.316% Subordinated Capital Income Securities, liquidation amount $1,000 per
Capital Security (the "Exchange Capital Securities"), which will have terms
substantially identical to the Capital Securities (except they will not contain
terms with respect to transfer restrictions under the Securities Act (other than
requiring minimum transfers thereof to be in blocks of $100,000 aggregate
liquidation amount), and will not provide for any Additional Distributions
thereon), and (iii) with respect to the Capital Securities Guarantee, the
Company's 

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guarantee (the "Exchange Capital Securities Guarantee") of the Exchange Capital
Securities which will have terms substantially identical to the Capital
Securities Guarantee.

     "Holders" shall mean the Initial Purchasers, for so long as they own any
Registrable Securities, and each of their respective successors, assigns and
direct and indirect transferees who become registered owners of Registrable
Securities under the Indenture or Declaration of Trust.

     "Indenture" shall mean the Indenture relating to the Subordinated
Debentures and the Exchange Debentures, dated as of May 28, 1997, between the
Company, as issuer, and First National Bank of Chicago, as trustee, as the same
may be amended from time to time in accordance with the terms thereof.

     "Initial Purchasers" shall have the meaning set forth in the preamble to
this Agreement.

     "Inspectors" shall have the meaning set forth in Section 3(n) hereof.

     "Issue Date" shall mean May 28, 1997, the date of original issuance of the
Securities.

     "Liquidated Damages" shall have the meaning set forth in Section 2(e)
hereof.

     "Majority Holders" shall mean the Holders of a majority of the aggregate
liquidation amount of outstanding Capital Securities.

     "Participating Broker-Dealer" shall have the meaning set forth in 
Section 3(w) hereof.
 
     "Person" shall mean an individual, partnership, corporation, trust or
unincorporated organization, limited liability company, or a government or
agency or political subdivision thereof.

     "Private Exchange" shall have the meaning set forth in Section 2(a) hereof.

     "Private Exchange Securities" shall have the meaning set forth in 
Section 2(a) hereof.

     "Prospectus" shall mean the prospectus included in a Registration
Statement, including any preliminary prospectus, and any such prospectus as
amended or supplemented by any prospectus supplement, including a prospectus
supplement with respect to the terms of the offering of any portion of the
Registrable Securities covered by a Shelf Registration Statement, and by all
other amendments and supplements to a prospectus, including post-effective
amendments, and in each case including all material incorporated by reference
therein.

     "Purchase Agreement" shall have the meaning set forth in the preamble to
this Agreement.

     "Records" shall have the meaning set forth in Section 3(n) hereof.

     "Registrable Securities" shall mean the Securities and, if issued, the
Private Exchange Securities; provided, however, that Securities or Private
Exchange Securities, as the case may be, shall cease to be Registrable
Securities when (i) a Registration Statement with respect to such 

                                      -3-
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Securities or Private Exchange Securities for the exchange or resale thereof, as
the case may be, shall have been declared effective under the Securities Act and
such Securities or Private Exchange Securities, as the case may be, shall have
been disposed of pursuant to such Registration Statement, (ii) such Securities
or Private Exchange Securities, as the case may be, shall have been sold to the
public pursuant to Rule 144(k) (or any similar provision then in force, but not
Rule 144A) under the Securities Act or are eligible to be sold without
restriction as contemplated by Rule 144(k), (iii) such Securities or Private
Exchange Securities, as the case may be, shall have ceased to be outstanding or
(iv) with respect to the Securities, such Securities shall have been exchanged
for Exchange Securities upon consummation of the Exchange Offer and are
thereafter freely tradeable by the holder thereof (other than an affiliate of
the Company).

     "Registration Expenses" shall mean any and all expenses incident to
performance of or compliance by the Company or the Trust with this Agreement,
including, without limitation:  (i) all SEC or National Association of
Securities Dealers, Inc. (the "NASD") registration and filing fees, including,
if applicable, the fees and expenses of any "qualified independent underwriter"
(and its counsel) that is required to be retained by any Holder of Registrable
Securities in accordance with the rules and regulations of the NASD, (ii) all
fees and expenses incurred in connection with compliance with state securities
or blue sky laws (including reasonable fees and disbursements of one counsel for
any underwriters or Holders in connection with blue sky qualification of any of
the Exchange Securities or Registrable Securities) and compliance with the rules
of the NASD, (iii) all expenses of any Persons in preparing or assisting in
preparing, word processing, printing and distributing any Registration
Statement, any Prospectus and any amendments or supplements thereto, and in
preparing or assisting in preparing, printing and distributing any underwriting
agreements, securities sales agreements and other documents relating to the
performance of and compliance with this Agreement, (iv) all rating agency fees,
(v) the fees and disbursements of counsel for the Company and the Trust and of
the independent certified public accountants of the Company, including the
expenses of any "cold comfort" letters required by or incident to such
performance and compliance, (vi) the fees and expenses of the Trustees, and any
exchange agent or custodian, (vii) all fees and expenses incurred in connection
with the listing, if any, of any of the Exchange Securities or the Registrable
Securities on any securities exchange or exchanges or on any securities
quotation system, and (viii) the reasonable fees and expenses of any special
experts retained by the Company or the Trust in connection with any Registration
Statement.

     "Registration Statement" shall mean any registration statement of the
Company and the Trust which covers any of the Exchange Securities or Registrable
Securities pursuant to the provisions of this Agreement, and all amendments and
supplements to any such Registration Statement, including post-effective
amendments, in each case including the Prospectus contained therein, all
exhibits thereto and all material incorporated by reference therein.

     "Rule 144(k) Period" shall mean the period of two years (or such shorter
period as may hereafter be referred to in Rule 144(k) under the Securities Act
(or similar successor rule)) commencing on the Issue Date.

     "SEC" shall mean the Securities and Exchange Commission.

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     "Securities" shall have the meaning set forth in the preamble to this
Agreement.

     "Securities Act" shall mean the Securities Act of 1933, as amended from
time to time.

     "Shelf Registration" shall mean a registration effected pursuant to 
Section 2(b) hereof.

     "Shelf Registration Event" shall have the meaning set forth in Section 2(b)
hereof.

     "Shelf Registration Event Date" shall have the meaning set forth in 
Section 2(b) hereof.

     "Shelf Registration Statement" shall mean a "shelf" registration statement
of the Company and the Trust pursuant to the provisions of Section 2(b) hereof
which covers all of the Registrable Securities or all of the Private Exchange
Securities, as the case may be, on an appropriate form under Rule 415 under the
Securities Act, or any similar rule that may be adopted by the SEC, and all
amendments and supplements to such registration statement, including post-
effective amendments, in each case including the Prospectus contained therein,
all exhibits thereto and all material incorporated by reference therein.

     "TIA" shall have the meaning set forth in Section 3(k) hereof.

     "Trustees" shall mean any and all trustees with respect to (i) the Capital
Securities under the Declaration, (ii) the Subordinated Debentures under the
Indenture and (iii) the Capital Securities Guarantee.

          2.   Registration Under the Securities Act.

          (a) Exchange Offer.  Except as set forth in Section 2(b) below, the
Company and the Trust shall, for the benefit of the Holders, use their
reasonable best efforts to (i) cause to be filed with the SEC within 150 days
after the Issue Date an Exchange Offer Registration Statement relating to the
Exchange Offer, (ii) cause such Exchange Offer Registration Statement to be
declared effective under the Securities Act by the SEC not later than the date
which is 180 days after the Issue Date, and (iii) keep such Exchange Offer
Registration Statement effective for not less than 30 calendar days (or longer
if required by applicable law) after the date notice of the Exchange Offer is
mailed to the Holders.  Upon the effectiveness of the Exchange Offer
Registration Statement, the Company and the Trust shall promptly commence the
Exchange Offer, it being the objective of such Exchange Offer to enable each
Holder eligible and electing to exchange Registrable Securities for a like
principal amount of Exchange Debentures or a like liquidation amount of Exchange
Capital Securities, together with the Exchange Guarantee, as applicable
(assuming that such Holder is not an affiliate of the Company within the meaning
of Rule 405 under the Securities Act and is not a broker-dealer tendering
Registrable Securities acquired directly from the Company for its own account,
acquires the Exchange Securities in the ordinary course of such Holder's
business and has no arrangements or understandings with any Person to
participate in the Exchange Offer for the purpose of distributing the Exchange
Securities) to transfer such Exchange Securities from and after their receipt
without any limitations or restrictions under the Securities Act and under state
securities or blue sky laws (other than requiring minimum transfers in blocks
having an aggregate principal 

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<PAGE>
 
or liquidation amount, as the case may be, of $100,000). The Company and the
Trust shall use their reasonable best efforts to cause the Exchange Offer to be
Consummated on the earliest practicable date after the Exchange Offer
Registration Statement has become effective.

          In connection with the Exchange Offer, the Company and the Trust
shall:

     (i)    mail to each Holder a copy of the Prospectus forming part of the
Exchange Offer Registration Statement, together with an appropriate letter of
transmittal and related documents;

     (ii)   keep the Exchange Offer open for acceptance for a period of not less
than 30 days after the date notice thereof is mailed to the Holders (or longer
if required by applicable law) (such period referred to herein as the "Exchange
Period");

     (iii)  utilize the services of the Depositary for the Exchange Offer;

     (iv)   permit Holders to withdraw tendered Securities at any time prior to
the close of business, New York time, on the last Business Day of the Exchange
Period, by sending to the institution specified in the notice, a telegram,
telex, facsimile transmission or letter setting forth the name of such Holder,
the liquidation amount or principal amount of Securities delivered for exchange,
and a statement that such Holder is withdrawing his election to have such
Securities exchanged;

     (v)    notify each Holder that any Security not tendered by such Holder in
the Exchange Offer will remain outstanding and continue to accrue interest or
accumulate distributions, as the case may be, but will not retain any rights
under this Agreement (except in the case of the Initial Purchasers and
Participating Broker-Dealers as provided herein); and

     (vi)   otherwise comply with all applicable laws relating to the Exchange
Offer.

            If any of the Initial Purchasers determine upon advice of their
outside counsel that they are not eligible to participate in the Exchange Offer
with respect to the exchange of Securities constituting any portion of an unsold
allotment in the initial distribution, as soon as practicable upon receipt by
the Company and the Trust of a written request from such Initial Purchaser, the
Company and the Trust, as applicable, shall issue and deliver to such Initial
Purchaser in exchange (the "Private Exchange") for the Securities held by such
Initial Purchaser, a like liquidation amount of Capital Securities of the Trust
or, in the event the Trust is liquidated and Subordinated Debentures are
distributed, a like principal amount of the Subordinated Debentures of the
Company, together with the Exchange Guarantee, in each case that are identical
(except that such securities may bear a customary legend with respect to
restrictions on transfer pursuant to the Securities Act) to the Exchange
Securities (the "Private Exchange Securities") and which are issued pursuant to
the Indenture, the Declaration or the Guarantee (which provides that the
Exchange Securities will not be subject to the transfer restrictions set forth
in the Indenture or the Declaration, as applicable (other than requiring minimum
transfers thereof to be in blocks of $100,000 aggregate principal amount or
liquidation amount, as the case may be), and that the Exchange Securities, the
Private Exchange Securities and the Securities will vote and consent together on
all matters as one class and that none of the Exchange Securities, the Private
Exchange Securities or the Securities will have the right to 

                                      -6-
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vote or consent as a separate class on any matter). The Private Exchange
Securities shall be of the same series as the Exchange Securities and the
Company and the Trust will seek to cause the CUSIP Service Bureau to issue the
same CUSIP Numbers for the Private Exchange Securities as for the Exchange
Securities issued pursuant to the Exchange Offer. If requested by the Company,
the Initial Purchasers will, within a reasonable time in advance of the
Company's filing of an Exchange Offer Registration Statement hereunder, advise
the Company as to the number of Registrable Securities held by it which
constitute an unsold allotment in the initial distribution.

            As soon as practicable after the close of the Exchange Offer and, if
applicable, the Private Exchange, the Company and the Trust, as the case
requires, shall:

     (i)    accept for exchange all Securities or portions thereof tendered and
not validly withdrawn pursuant to the Exchange Offer or the Private Exchange;

     (ii)   deliver, or cause to be delivered, to the applicable Trustee for
cancellation all Securities or portions thereof so accepted for exchange by the
Company; and

     (iii)  issue, and cause the applicable Trustee under the Indenture, the
Declaration or the Guarantee, as applicable, to promptly authenticate and
deliver to each Holder, new Exchange Securities or Private Exchange Securities,
as applicable, equal in principal amount to the principal amount of the
Subordinated Debentures or equal in liquidation amount to the liquidation amount
of the Capital Securities (together with the guarantee thereof) as are
surrendered by such Holder.

            Distributions on each Exchange Capital Security and interest on each
Exchange Debenture and Private Exchange Security issued pursuant to the Exchange
Offer and in the Private Exchange will accrue from the last date on which a
distribution or interest was paid on the Capital Security or the Subordinated
Debenture surrendered in exchange therefor or, if no distribution or interest
has been paid on such Capital Security or Subordinated Debenture, from the Issue
Date.  To the extent not prohibited by any law or applicable interpretations of
the staff of the SEC, the Company and the Trust shall use their reasonable best
efforts to complete the Exchange Offer as provided above, and shall comply with
the applicable requirements of the Securities Act, the Exchange Act and other
applicable laws in connection with the Exchange Offer.  The Exchange Offer shall
not be subject to any conditions, other than that the Exchange Offer does not
violate applicable law or any applicable interpretation of the staff of the SEC.
Each Holder of Registrable Securities (other than Participating Broker-Dealers)
who wishes to exchange such Registrable Securities for Exchange Securities in
the Exchange Offer will be required to represent that (i) it is not an affiliate
of the Trust or the Company, (ii) the Exchange Securities to be received by it
were acquired in the ordinary course of its business and (iii) at the time of
the Exchange Offer, it has no arrangement with any person to participate in the
distribution (within the meaning of the Securities Act) of the Exchange Capital
Securities.  Each Participating Broker-Dealer shall be required to make such
representations as, in the reasonable judgment of the Company and the Trust, may
be necessary under applicable SEC rules, regulations or interpretations or
customary in connection with similar exchange offers.  Each Holder (including
Participating Broker-Dealers) shall be required to make such other
representations as may be reasonably necessary under applicable SEC rules,
regulations or interpretations to render the use of Form S-4 or another
appropriate form under the Securities Act 

                                      -7-
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available and will be required to agree to comply with their agreements and
covenants set forth in this Agreement. The Company and the Trust shall inform
the Initial Purchaser, after consultation with the applicable Trustees, of the
names and addresses of the Holders to whom the Exchange Offer is made, and the
Initial Purchasers shall have the right to contact such Holders and otherwise
facilitate the tender of Registrable Securities in the Exchange Offer.

          Prior to effectiveness of the Exchange Offer Registration Statement,
the Company and the Trust shall, if requested by the staff of the SEC, provide a
supplemental letter to the SEC (i) stating that the Company and the Trust are
registering the Exchange Offer in reliance on the position of the SEC enunciated
in Exxon Capital Holdings Corporation (available May 13, 1988) and Morgan
Stanley and Co., Inc. (available June 5, 1991) and (ii) including a
representation that the Company and the Trust have not entered into any
arrangement or understanding with any Person to distribute the Exchange
Securities and that, to the best of the Company's and the Trust's information
and belief, each Holder participating in the Exchange Offer is acquiring the
Exchange Securities in its ordinary course of business and has no arrangement or
understanding with any Person to participate in the distribution of the Exchange
Securities received in the Exchange Offer.

          If in the reasonable opinion of counsel to the Company and the Trust
there is a question as to whether the Exchange Offer is permitted by applicable
law, the Company and the Trust hereby agree to seek a no-action letter or other
favorable decision from the SEC allowing the Company and the Trust to consummate
the Exchange Offer.  The Company and the Trust hereby agree to pursue the
issuance of such a decision to the SEC staff level, but shall not be required to
take commercially unreasonable action to effect a change of SEC policy.  The
Company and the Trust hereby agree, however, to (i) participate in telephonic
conferences with the SEC and the staff of the SEC, (ii) deliver to the staff of
the SEC an analysis prepared by counsel to the Company setting forth the legal
bases, if any, upon which such counsel has concluded that the Exchange Offer
should be permitted and (iii) diligently pursue a resolution (which need not be
favorable) by the staff of the SEC of such submission.

          Upon Consummation of the Exchange Offer in accordance with this
Section 2(a), the provisions of this Agreement shall continue to apply, mutatis
mutandis, solely with respect to Registrable Securities that are Private
Exchange Securities and Exchange Securities held by Participating Broker-
Dealers, and the Company and the Trust shall have no further obligation to
register the Registrable Securities (other than Private Exchange Securities)
held by any Holder (other than an Initial Purchaser or a Participating Broker-
Dealer) pursuant to Section 2(b) of this Agreement.

          (b) Shelf Registration.  In the event that (i) the Company, the Trust
or the Majority Holders reasonably determine, after conferring with counsel,
that the Exchange Offer Registration provided in Section 2(a) above is not
available under applicable laws and regulations and currently prevailing
interpretations of the staff of the SEC, (ii) the Company shall determine in
good faith that there is a reasonable likelihood that, or that a material
uncertainty exists as to whether, consummation of the Exchange Offer would
result in (x) the Trust becoming subject to United States federal income tax
with respect to income received or accrued on the Subordinated Debentures or the
Exchange Debentures (collectively, the "Debentures"), (y) interest payable by
the 

                                      -8-
<PAGE>
 
Company on the Debentures not being deductible by the Company, in whole or
in part, for United States federal income tax purposes or (z) the Trust becoming
subject to more than a de minimus amount of other taxes, duties or governmental
charges, (iii) the Exchange Offer Registration Statement is not declared
effective within 180 days of the Issue Date or (iv) upon the request of the
Initial Purchasers with respect to any Registrable Securities held by them, if
such Initial Purchasers are not permitted, in the opinion of Baker & Botts,
L.L.P., pursuant to applicable law or applicable interpretations of the staff of
the SEC, to participate in the Exchange Offer and thereby receive securities
that are freely tradeable without restriction under the Securities Act and
applicable blue sky or state securities laws (any of the events specified in
(i)-(iv) being a "Shelf Registration Event" and the date of occurrence thereof,
the "Shelf Registration Event Date"), then in addition to or in lieu of
conducting the Exchange Offer contemplated by Section 2(a), as the case may be,
the Company and the Trust shall promptly deliver to the Holders and the Delaware
Trustee (as defined in the Declaration) written notice thereof and shall use
their reasonable best efforts to cause to be filed as promptly as practicable
after such Shelf Registration Event Date, as the case may be, and, in any event,
within 45 days after such Shelf Registration Event Date (provided that in no
event shall such date be earlier than 75 days after the Issue Date), a Shelf
Registration Statement providing for the sale by the Holders of all of the
Registrable Securities, and shall use its reasonable best efforts to have such
Shelf Registration Statement declared effective by the SEC as soon as
practicable.  No Holder of Registrable Securities shall be entitled to include
any of its Registrable Securities in any Shelf Registration pursuant to this
Agreement unless and until such Holder agrees in writing to be bound by all of
the provisions of this Agreement applicable to such Holder and furnishes to the
Company and the Trust in writing, within 15 days after receipt of a request
therefor, such information as the Company and the Trust may, after conferring
with counsel with regard to information relating to Holders that would be
required by the SEC to be included in such Shelf Registration Statement or
Prospectus included therein, reasonably request for inclusion in any Shelf
Registration Statement or Prospectus included therein.  Each Holder as to which
any Shelf Registration is being effected agrees to furnish to the Company and
the Trust all information with respect to such Holder necessary to make the
information previously furnished to the Company by such Holder not materially
misleading.

          The Company and the Trust agree to use their reasonable best efforts
to keep the Shelf Registration Statement continuously effective and usable for
resales for (a) the Rule 144(k) Period in the case of a Shelf Registration
Statement filed pursuant to Section 2(b)(i), (ii) or (iii) or (b) 180 days in
the case of a Shelf Registration Statement filed pursuant to Section 2(b)(iv)
(subject in each case to extension pursuant to the last paragraph of Section 3
hereof), or for such shorter period which will terminate when all of the
Registrable Securities covered by the Shelf Registration Statement have been
sold pursuant to the Shelf Registration Statement or cease to be outstanding
(the "Effectiveness Period").  The Company and the Trust shall not permit any
securities other than Registrable Securities to be included in the Shelf
Registration.  The Company and the Trust will, in the event a Shelf Registration
Statement is declared effective, provide to each Holder a reasonable number of
copies of the Prospectus which is a part of the Shelf Registration Statement and
notify each such Holder when the Shelf Registration has become effective.  The
Company and the Trust further agree, if necessary, to supplement or amend the
Shelf Registration Statement, if required by the rules, regulations or
instructions applicable to the registration form used by the Company for such
Shelf Registration Statement or by the Securities Act or by any other rules and
regulations 

                                      -9-
<PAGE>
 
thereunder for shelf registrations, and the Company and the Trust agree to
furnish to the Holders of Registrable Securities copies of any such supplement
or amendment promptly after its being used or filed with the SEC.

          (c) Expenses.  The Company, as issuer of the Subordinated Debentures,
shall pay all Registration Expenses in connection with any Registration
Statement filed pursuant to Section 2(a) and/or 2(b) hereof and will reimburse
the Initial Purchasers for the reasonable fees and disbursements of Baker &
Botts, L.L.P., counsel for the Initial Purchasers, incurred in connection with
the Exchange Offer and, if applicable, the Private Exchange, or any one other
counsel designated in writing by the Majority Holders to act as counsel for the
Holders of the Registrable Securities in connection with a Shelf Registration
Statement, which other counsel shall be reasonably satisfactory to the Company.
Except as provided herein, each Holder shall pay all expenses of its counsel and
any of its other advisors or experts, underwriting discounts and commissions and
transfer taxes, if any, relating to the sale or disposition of such Holder's
Registrable Securities pursuant to the Shelf Registration Statement.

          (d) Effective Registration Statement.  An Exchange Offer Registration
Statement pursuant to Section 2(a) hereof or a Shelf Registration Statement
pursuant to Section 2(b) hereof will not be deemed to have become effective
unless it has been declared effective by the SEC; provided, however, that if,
after it has been declared effective, the offering of Registrable Securities
pursuant to such Exchange Offer Registration Statement or Shelf Registration
Statement is interfered with by any stop order, injunction or other order or
requirement of the SEC or any other governmental agency or court, such
Registration Statement will be deemed not to have been effective during the
period of such interference, until the offering of Registrable Securities
pursuant to such Registration Statement may legally resume.  The Company and the
Trust will be deemed not to have used their reasonable best efforts to cause the
Exchange Offer Registration Statement or the Shelf Registration Statement, as
the case may be, to become, or to remain, effective during the requisite period
if either of them voluntarily takes any action that would result in any such
Registration Statement not being declared effective or that would result in the
Holders of Registrable Securities covered thereby not being able to exchange or
offer and sell such Registrable Securities during that period unless such action
is required by applicable laws and regulations or currently prevailing
interpretations of the staff of the SEC.

          (e) Liquidated Damages.  In the event that (i) (A) neither the
Exchange Offer Registration Statement nor a Shelf Registration Statement is
filed with the SEC on or prior to the 150th day after the Issue Date or (B)
notwithstanding that the Company and the Trust have consummated or will
consummate an Exchange Offer, the Company and the Trust are required to file a
Shelf Registration Statement and the Shelf Registration Statement is not filed
on or prior to the 45th day after the Shelf Registration Event Date in respect
of a Shelf Registration Event attributable to any of the events set forth in
Sections 2(b)(i), (ii) and (iii) (provided that in no event shall such date be
earlier than 75 days after the Issue Date), then commencing on the day after the
applicable required filing date, liquidated damages ("Liquidated Damages") shall
accrue on the principal amount of the Subordinated Debentures, and additional
distributions ("Additional Distributions") shall accumulate on the liquidation
amount of the Trust Securities (as such term is defined in the Declaration),
each at a rate of .25% per annum; or

                                      -10-
<PAGE>
 
     (ii)   (A) neither the Exchange Offer Registration Statement nor a Shelf
Registration Statement is declared effective by the SEC on or prior to the 180th
day after the Issue Date (in the case of an Exchange Offer Registration
Statement) or on or prior to the later of (x) the 30th day after the date such
Shelf Registration Statement was required to be filed and (y) the 180th date
after the Issue Date (in the case of a Shelf Registration Statement in respect
of a Shelf Registration Event attributable to any of the events set forth in
Sections 2(b)(i), (ii) and (iii)), or (B) notwithstanding that the Company and
the Trust have consummated or will consummate an Exchange Offer, the Company and
the Trust are required to file a Shelf Registration Statement and such Shelf
Registration Statement is not declared effective by the Commission on or prior
to the 30th day after the date such Shelf Registration Statement was required to
be filed, then, commencing on the 181st day after the Issue Date (in the case of
an Exchange Offer Registration Statement) or the later of (A) the 31st day after
the date such Shelf Registration Statement was required to be filed and (B) the
181st day after the Issue Date (in the case of a Shelf Registration Statement in
respect of a Shelf Registration Event attributable to any of the events set
forth in Sections 2(b)(i), (ii) and (iii)), Liquidated Damages shall accrue on
the principal amount of the Subordinated Debentures, and Additional
Distributions shall accumulate on the liquidation amount of the Trust
Securities, each at a rate of .25% per annum; or

     (iii)  (A)  the Trust has not exchanged Exchange Capital Securities or
the Company has not exchanged Exchange Guarantees or Exchange Subordinated
Debentures for all Capital Securities, Guarantees or Subordinated Debentures, as
the case may be, validly tendered, in accordance with the terms of the Exchange
Offer on or prior to the 45th day after the date on which the Exchange Offer
Registration Statement was declared effective or (B) if applicable, the Shelf
Registration Statement in respect of a Shelf Registration Event attributable to
any of the events set forth in Sections 2(b)(i), (ii) and (iii) has been
declared effective and such Shelf Registration Statement ceases to be effective
or usable for resales (whether as a result of an event contemplated by Section
3(e) or otherwise) at any time prior to the expiration of the Rule 144(k) Period
(other than after such time as all Securities have been disposed of thereunder
or otherwise cease to be Registrable Securities), then Liquidated Damages shall
accrue on the principal amount of Subordinated Debentures, and Additional
Distributions shall accumulate on the liquidation amount of the Trust
Securities, each at a rate of .25% per annum commencing on (x) the 46th day
after such effective date, in the case of (A) above, or (y) the day such Shelf
Registration Statement ceases to be effective or usable for resales in the case
of (B) above;

     Provided, however, that neither the Liquidated Damages rate on the
Subordinated Debentures, nor the Additional Distribution rate on the liquidation
amount of the Trust Securities, may exceed in the aggregate .25% per annum;
provided, further, however, that (1) upon the filing of the Exchange Offer
Registration Statement or a Shelf Registration Statement (in the case of clause
(i) above), (2) upon the effectiveness of the Exchange Offer Registration
Statement or a Shelf Registration Statement (in the case of clause (ii) above),
(3) upon the exchange of Exchange Capital Securities, Exchange Guarantees and
Exchange Debentures for all Capital Securities, Guarantees and Subordinated
Debentures tendered (in the case of clause (iii)(A) above), or at such time as
the Shelf Registration Statement which had ceased to remain effective or usable
for resales again becomes effective and usable for resales (in the case of
clause (iii)(B) above), or (4) in any case, at such time 

                                      -11-
<PAGE>
 
as there are no longer any outstanding Registrable Securities, Liquidated
Damages on the principal amount of the Subordinated Debentures and Additional
Distributions on the liquidation amount of the Trust Securities as a result of
such clause (or the relevant subclause thereof) shall cease to accrue and
accumulate.

     Any amounts of Liquidated Damages and Additional Distributions due pursuant
to Section 2(e)(i), (ii) or (iii) above will be payable in cash on the next
succeeding June 1 and December 1, as the case may be, to Holders on the relevant
record dates for the payment of interest and distributions pursuant to the
Indenture and the Declaration, respectively.

          (f) Specific Enforcement.  Without limiting the remedies available to
the Holders, the Company and the Trust acknowledge that any failure by the
Company or the Trust to comply with its obligations under Section 2(a) and
Section 2(b) hereof may result in material irreparable injury to the Initial
Purchasers or any Holder for which there is no adequate remedy at law, that it
would not be possible to measure damages for such injuries precisely and that,
in the event of any such failure, the Initial Purchasers or any Holder may
obtain such relief as may be required to specifically enforce the Company's and
the Trust's obligations under Section 2(a) and Section 2(b) hereof.

          (g) Distribution of Subordinated Debentures.  Notwithstanding any
other provisions of this Agreement, in the event that Subordinated Debentures
are distributed to Holders of Capital Securities in liquidation of the Trust
pursuant to the Declaration, (i) all references in this Section 2 and in Section
3 to Securities, Registrable Securities and Exchange Securities shall not
include the Capital Securities and Capital Securities Guarantee or Exchange
Capital Securities and Exchange Capital Securities Guarantee issued or to be
issued in exchange therefor in the Exchange Offer and (ii) all requirements for
action to be taken by the Trust in this Section 2 and in Section 3 shall cease
to apply and all requirements for action to be taken by the Company in this
Section 2 and in Section 3 shall apply to the Subordinated Debentures and
Exchange Debentures issued or to be issued in exchange therefor in the Exchange
Offer.

          3.  Registration Procedures.  In connection with the obligations of
the Company and the Trust with respect to the Registration Statements pursuant
to Sections 2(a) and 2(b) hereof, each of the Company and the Trust shall:

          (a) use their reasonable best efforts to prepare and file with the SEC
     a Registration Statement or Registration Statements as prescribed by
     Sections 2(a) and 2(b) hereof within the relevant time period specified in
     Section 2 hereof on the appropriate form under the Securities Act, which
     form (i) shall be selected by the Company and the Trust, (ii) shall, in the
     case of a Shelf Registration, be available for the sale of the Registrable
     Securities by the selling Holders thereof and, in the case of an Exchange
     Offer, be available for the exchange of Registrable Securities, and (iii)
     shall comply as to form in all material respects with the requirements of
     the applicable form and include all financial statements required by the
     SEC to be filed therewith; and use its best efforts to cause such
     Registration Statement to become effective and remain effective (and, in
     the case of a Shelf Registration Statement, usable for resales) in
     accordance with Section 2 hereof; provided, however, that if (1) such

                                      -12-
<PAGE>
 
     filing is pursuant to Section 2(b), or (2) a Prospectus contained in an
     Exchange Offer Registration Statement filed pursuant to Section 2(a) is
     required to be delivered under the Securities Act by any Participating
     Broker-Dealer who seeks to sell Exchange Securities, before filing any
     Registration Statement or Prospectus or any amendments or supplements
     thereto, the Company and the Trust shall furnish to and afford the Holders
     of the Registrable Securities (in the case of a Shelf Registration) or each
     such Participating Broker-Dealer, as the case may be, covered by such
     Registration Statement, their counsel and the managing underwriters, if
     any, a reasonable opportunity to review copies of all such documents
     proposed to be filed.  The Company and the Trust shall not file any
     Registration Statement or Prospectus or any amendments or supplements
     thereto in respect of which the Holders must be afforded an opportunity to
     review prior to the filing of such documents if the Majority Holders or
     such Participating Broker-Dealer, as the case may be, their counsel or the
     managing underwriters, if any, shall reasonably object;

          (b) use their reasonable best efforts to prepare and file with the SEC
     such amendments and post-effective amendments to each Registration
     Statement as may be necessary to keep such Registration Statement effective
     for the Effectiveness Period or the Applicable Period, as the case may be;
     and cause each Prospectus to be supplemented, if so determined by the
     Company or the Trust or requested by the SEC, by any required prospectus
     supplement and as so supplemented to be filed pursuant to Rule 424 (or any
     similar provision then in force) under the Securities Act, and comply with
     the provisions of the Securities Act, the Exchange Act and the rules and
     regulations promulgated thereunder applicable to it with respect to the
     disposition of all securities covered by each Registration Statement during
     the Effectiveness Period or the Applicable Period, as the case may be, in
     accordance with the intended method or methods of distribution by the
     selling Holders thereof described in this Agreement (including sales by any
     Participating Broker-Dealer);

          (c) in the case of a Shelf Registration, (i) notify each Holder of
     Registrable Securities included in the Shelf Registration Statement, at
     least five Business Days prior to filing, that a Shelf Registration
     Statement with respect to the Registrable Securities is being filed and
     advising such Holder that the distribution of Registrable Securities will
     be made in accordance with the method selected by the Majority Holders; and
     (ii) furnish to each Holder of Registrable Securities included in the Shelf
     Registration Statement and to each underwriter of an underwritten offering
     of Registrable Securities, if any, without charge, as many copies of each
     Prospectus, including each preliminary Prospectus, and any amendment or
     supplement thereto and such other documents as such Holder or underwriter
     may reasonably request, in order to facilitate the public sale or other
     disposition of the Registrable Securities; and (iii) consent to the use of
     the Prospectus or any amendment or supplement thereto by each of the
     selling Holders of Registrable Securities included in the Shelf
     Registration Statement in connection with the offering and sale of the
     Registrable Securities covered by the Prospectus or any amendment or
     supplement thereto;

          (d) use its reasonable best efforts to register or qualify the
     Registrable Securities and the Exchange Securities  under all applicable
     state securities or blue sky laws of such jurisdictions by the time the
     applicable Registration Statement is declared effective by the 

                                      -13-
<PAGE>
 
     SEC as any Holder of Registrable Securities covered by a Registration
     Statement and each underwriter of an underwritten offering of Registrable
     Securities shall reasonably request in writing in advance of such date of
     effectiveness, and do any and all other acts and things which may be
     reasonably necessary or advisable to enable such Holder and underwriter to
     consummate the disposition in each such jurisdiction of such Registrable
     Securities owned by such Holder; provided, however, that the Company and
     the Trust shall not be required to (i) qualify as a foreign corporation or
     as a dealer in securities in any jurisdiction where it would not otherwise
     be required to qualify but for this Section 3(d), (ii) file any general
     consent to service of process in any jurisdiction where it would not
     otherwise be subject to such service of process or (iii) subject itself to
     taxation in any such jurisdiction if it is not then so subject;

          (e) (1)  in the case of a Shelf Registration or (2) if Participating
     Broker-Dealers from whom the Company or the Trust has received prior
     written notice that they will be utilizing the Prospectus contained in the
     Exchange Offer Registration Statement as provided in Section 3(t) hereof
     are seeking to sell Exchange Securities and are required to deliver
     Prospectuses, notify each Holder of Registrable Securities, or such
     Participating Broker-Dealers, as the case may be, their counsel and the
     managing underwriters, if any, promptly and promptly confirm such notice in
     writing (i) when a Registration Statement has become effective and when any
     post-effective amendments and supplements thereto become effective, (ii) of
     any request by the SEC or any state securities authority for amendments and
     supplements to a Registration Statement or Prospectus or for additional
     information after the Registration Statement has become effective, (iii) of
     the issuance by the SEC or any state securities authority of any stop order
     suspending the effectiveness of a Registration Statement or the
     qualification of the Registrable Securities or the Exchange Securities to
     be offered or sold by any Participating Broker-Dealer in any jurisdiction
     described in paragraph 3(d) hereof or the initiation of any proceedings for
     that purpose, (iv) in the case of a Shelf Registration, if, between the
     effective date of a Registration Statement and the closing of any sale of
     Registrable Securities covered thereby, the representations and warranties
     of the Company and the Trust contained in any purchase agreement,
     securities sales agreement or other similar agreement, if any cease to be
     true and correct in all material respects, (v) of the happening of any
     event or the failure of any event to occur or the discovery of any facts or
     otherwise, during the Effectiveness Period, which makes any statement made
     in such Registration Statement or the related Prospectus untrue in any
     material respect or which causes such Registration Statement or Prospectus
     to omit to state a material fact necessary to make the statements therein,
     in the light of the circumstances under which they were made, not
     misleading, and (vi) the Company and the Trust's reasonable determination
     that a post-effective amendment to the Registration Statement would be
     appropriate;

          (f) make every reasonable effort to obtain the withdrawal of any order
     suspending the effectiveness of a Registration Statement at the earliest
     possible moment;

          (g) in the case of a Shelf Registration, furnish to each Holder of
     Registrable Securities included within the coverage of such Shelf
     Registration Statement, without charge, one conformed copy of each
     Registration Statement relating to such Shelf Registration and 

                                      -14-
<PAGE>
 
     any post-effective amendment thereto (without documents incorporated
     therein by reference or exhibits thereto, unless requested);

          (h) in the case of a Shelf Registration, cooperate with the selling
     Holders of Registrable Securities to facilitate the timely preparation and
     delivery of certificates representing Registrable Securities to be sold and
     not bearing any restrictive legends (other than with respect to
     restrictions requiring minimum transfers in blocks having an aggregate
     principal or liquidation amount, as the case may be, of $100,000) and in
     such denominations (consistent with the provisions of the Indenture and the
     Declaration) and registered in such names as the selling Holders or the
     underwriters may reasonably request at least two Business Days prior to the
     closing of any sale of Registrable Securities pursuant to such Shelf
     Registration Statement;

          (i) in the case of a Shelf Registration or an Exchange Offer
     Registration, upon the occurrence of any circumstance contemplated by
     Section 3(e)(ii), 3(e)(iii), 3(e)(v) or 3(e)(vi) hereof, use its reasonable
     best efforts to prepare a supplement or post-effective amendment to such
     Registration Statement or the related Prospectus or any document
     incorporated therein by reference or file any other required document so
     that, as thereafter delivered to the purchasers of the Registrable
     Securities, such Prospectus will not contain any untrue statement of a
     material fact or omit to state a material fact necessary to make the
     statements therein, in the light of the circumstances under which they were
     made, not misleading; and to notify each Holder to suspend use of the
     Prospectus as promptly as practicable after the occurrence of such an
     event, and each Holder hereby agrees to suspend use of the Prospectus until
     the Company has amended or supplemented the Prospectus to correct such
     misstatement or omission;

          (j) obtain a CUSIP number for all Exchange Capital Securities and the
     Capital Securities (and if the Trust has made a distribution of the
     Subordinated Debentures to the Holders of the Capital Securities, the
     Subordinated Debentures or the Exchange Debentures), as the case may be,
     not later than the effective date of a Registration Statement, and provide
     the Trustee with printed certificates for the Exchange Securities or the
     Registrable Securities, as the case may be, in a form eligible for deposit
     with the Depositary;

          (k) cause the Indenture, the Declaration, the Guarantee and the
     Exchange Guarantee to be qualified under the Trust Indenture Act of 1939
     (the "TIA") in connection with the registration of the Exchange Securities
     or Registrable Securities, as the case may be, and effect such changes to
     such documents as may be required for them to be so qualified in accordance
     with the terms of the TIA and execute, and use its reasonable best efforts
     to cause the relevant trustee to execute, all documents as may be required
     to effect such changes, and all other forms and documents required to be
     filed with the SEC to enable such documents to be so qualified in a timely
     manner;

          (l) in the case of a Shelf Registration, enter into such agreements
     (including underwriting agreements) as are customary in underwritten
     offerings and take all such other appropriate actions in connection
     therewith as are reasonably requested by the Holders of at 

                                      -15-
<PAGE>
 
     least 25% in aggregate principal or liquidation amount, as the case may be,
     of the Registrable Securities in order to expedite or facilitate the
     registration or the disposition of the Registrable Securities; provided,
     that the Company and the Trust shall not be required to enter into any such
     agreement more than twice with respect to all of the Registrable Securities
     and may delay entering into such an agreement until the consummation of any
     underwritten public offering which the Company shall have undertaken;

          (m) in the case of a Shelf Registration, whether or not an
     underwriting agreement is entered into and whether or not the registration
     is an underwritten registration, if requested by (x) the Initial
     Purchasers, in the case where such Initial Purchasers hold Securities
     acquired as part of their initial distribution or (y) Holders of at least
     25% in aggregate principal or liquidation amount, as the case may be, of
     the Registrable Securities covered thereby:  (i) make such representations
     and warranties to Holders of the Registrable Securities and the
     underwriters (if any) with respect to the business of the Trust, the
     Company and its subsidiaries as then conducted and the Registration
     Statement, Prospectus and documents, if any, incorporated or deemed to be
     incorporated by reference therein, in each case, as are customarily made by
     issuers of debt securities to underwriters in underwritten offerings, and
     confirm the same if and when requested; (ii) obtain opinions of counsel to
     the Company and the Trust upon the effectiveness of such registration
     statement and, in the case of an underwritten offering, updates thereof
     (which may be in the form of a reliance letter) in form and substance
     reasonably satisfactory to the managing underwriters (if any) and the
     Holders of a majority in principal amount of the Registrable Securities
     being sold, addressed to each selling Holder and the underwriters (if any)
     covering the matters customarily covered in opinions requested in
     underwritten offerings and such other matters as may be reasonably
     requested by such underwriters (it being agreed that the matters to be
     covered by such opinion may be subject to customary qualifications and
     exceptions); (iii) obtain "cold comfort" letters upon the effectiveness of
     such registration statement and, in the case of an underwritten offering,
     updates thereof in form and substance reasonably satisfactory to the
     managing underwriters from the independent certified public accountants of
     the Company and the Trust (and, if necessary, any other independent
     certified public accountants of any subsidiary of the Company and the Trust
     or of any business acquired by the Company and the Trust for which
     financial statements and financial data are, or are required to be,
     included in the Registration Statement), addressed to each of the
     underwriters, such letters to be in customary form and covering matters of
     the type customarily covered in "cold comfort" letters in connection with
     underwritten offerings and such other matters as reasonably requested by
     such underwriters in accordance with Statement on Auditing Standards No.
     72; (iv) deliver such documents and certificates as may be reasonably
     requested and as are customarily delivered in similar offerings; and (v) if
     an underwriting agreement is entered into, provide indemnification pursuant
     to indemnification provisions and procedures no less favorable than those
     set forth in Section 4 hereof (or such other provisions and procedures
     acceptable to Holders of a majority in aggregate principal amount or
     liquidation amount, as the case may be, of Registrable Securities covered
     by such Registration Statement and the managing underwriters and agents)
     with respect to all parties to be indemnified pursuant to said Section
     (including, without limitation, such underwriters 

                                      -16-
<PAGE>
 
     and selling Holders). The above shall be done at each closing under such
     underwriting agreement, or as and to the extent required thereunder;

          (n) if (1) a Shelf Registration is filed pursuant to Section 2(b) or
     (2) a Prospectus contained in an Exchange Offer Registration Statement
     filed pursuant to Section 2(a) is required to be delivered under the
     Securities Act by any Participating Broker-Dealer who seeks to sell
     Exchange Securities during the Applicable Period, make reasonably available
     for inspection by any selling Holder of such Registrable Securities or
     Participating Broker-Dealer, as applicable, who certifies to the Company
     and the Trust that it has a current intention to sell Registrable
     Securities pursuant to the Shelf Registration, any underwriter
     participating in any such disposition of Registrable Securities, if any,
     and any attorney, accountant or other agent retained by any such selling
     Holder or each such Participating Broker-Dealer, as the case may be, or
     underwriter (collectively, the "Inspectors"), at the offices where normally
     kept, during the Company's normal business hours, all financial and other
     records, pertinent corporate documents and properties of the Trust, the
     Company and its subsidiaries (collectively, the "Records") as shall be
     reasonably necessary to enable them to exercise any applicable due
     diligence responsibilities, and cause the officers, directors and employees
     of the Trust, the Company and its subsidiaries to supply all relevant
     information, in each case reasonably requested by any such Inspector in
     connection with such Registration Statement.  Records which the Company and
     the Trust determine, in good faith, to be confidential and any records
     which it notifies the Inspectors are confidential shall not be disclosed by
     the Inspectors unless (i) the disclosure of such Records is necessary to
     avoid or correct a material misstatement or omission in such Registration
     Statement, (ii) subject to the last sentence of this Section 3(n), the
     release of such Records is ordered pursuant to a subpoena or other order
     from a court of competent jurisdiction or is necessary in connection with
     any action, suit or proceeding or (iii) the information in such Records has
     been made generally available to the public (other than by an Inspector or
     a selling Holder in breach of its obligations hereunder).  Each selling
     Holder of such Registrable Securities and each such Participating Broker-
     Dealer will be required to agree in writing that information obtained by it
     as a result of such inspections shall be deemed confidential and shall not
     be used by it as the basis for any market transactions in the securities of
     the Trust or the Company unless and until such is made generally available
     to the public through no fault of an Inspector or a selling Holder.  Each
     selling Holder of such Registrable Securities and each such Participating
     Broker-Dealer will be required to further agree in writing that it will,
     upon learning that disclosure of such Records is sought in a court of
     competent jurisdiction or in connection with any action, suit or
     proceeding, give notice to the Company and allow the Company at its expense
     to undertake appropriate action to prevent disclosure of the Records deemed
     confidential;

          (o) comply in all material respects with all applicable rules and
     regulations of the SEC so long as any provision of this Agreement shall be
     applicable and make generally available to its security holders earning
     statements satisfying the provisions of Section ll(a) of the Securities Act
     and Rule 158 thereunder (or any similar rule promulgated under the
     Securities Act) no later than 45 days after the end of any 12-month period
     (or 90 days after the end of any 12-month period if such period is a fiscal
     year) (i) commencing at the end of 

                                      -17-
<PAGE>
 
     any fiscal quarter in which Registrable Securities are sold to underwriters
     in a firm commitment or best efforts underwritten offering and (ii) if not
     sold to underwriters in such an offering, commencing on the first day of
     the first fiscal quarter of the Company after the effective date of a
     Registration Statement, which statements shall cover said 12-month periods;

          (p) upon consummation of an Exchange Offer or a Private Exchange, if
     requested by a Trustee, obtain an opinion of counsel to the Company
     addressed to the Trustee for the benefit of all Holders of Registrable
     Securities participating in the Exchange Offer or the Private Exchange, as
     the case may be, to the effect that (i) the Company and the Trust, as the
     case requires, has duly authorized, executed and delivered the Exchange
     Securities and Private Exchange Securities, and (ii) each of the Exchange
     Securities or the Private Exchange Securities, as the case may be,
     constitutes a legal, valid and binding obligation of the Company or the
     Trust, as the case requires, enforceable against the Company or the Trust,
     as the case requires, in accordance with its respective terms (in each
     case, with customary exceptions);

          (q) if an Exchange Offer or a Private Exchange is to be consummated,
     upon delivery of the Registrable Securities by Holders to the Company or
     the Trust, as applicable (or to such other Person as directed by the
     Company or the Trust, respectively), in exchange for the Exchange
     Securities or the Private Exchange Securities, as the case may be, the
     Company or the Trust, as applicable, shall mark, or cause to be marked, on
     such Registrable Securities delivered by such Holders that such Registrable
     Securities are being canceled in exchange for the Exchange Securities or
     the Private Exchange Securities, as the case may be; in no event shall such
     Registrable Securities be marked as paid or otherwise satisfied;

          (r) cooperate with each seller of Registrable Securities covered by
     any Registration Statement and each underwriter, if any, participating in
     the disposition of such Registrable Securities and their respective counsel
     in connection with any filings required to be made with the NASD;

          (s) use its reasonable best efforts to take all other steps necessary
     to effect the registration of the Registrable Securities covered by a
     Registration Statement contemplated hereby;

          (t) (A) in the case of an Exchange Offer, furnish one firm of legal
     counsel for the Initial Purchasers and (B) in the case of a Shelf
     Registration, furnish one firm of legal counsel for the Holders of
     Registrable Securities covered thereby copies of any request received by or
     on behalf of the Company or the Trust, from the SEC or any state securities
     authority for amendments or supplements to the relevant Registration
     Statement and Prospectus or for additional information;

          (u) in the case of a Shelf Registration and if requested by the
     managing underwriters, if any, or the Holders of a majority in aggregate
     principal amount of the Registrable Securities subject to the Shelf
     Registration Statement, (i) as soon as practicable 

                                      -18-
<PAGE>
 
     incorporate in a prospectus supplement or post-effective amendment such
     information or revisions to information therein relating to such
     Underwriters or selling Holders as the managing underwriters, if any, or
     such Holders or their counsel reasonably request to be included or made
     therein, (ii) make all required filings of such prospectus supplement or
     such post-effective amendment as soon as practicable after the Company and
     the Trust have received notification of the matters to be incorporated in
     such prospectus supplement or post-effective amendment and (iii) supplement
     or make amendments to such Shelf Registration Statement;

          (v) use their reasonable best efforts to cause the Exchange
     Securities, if applicable, to be rated with not more than two rating
     agencies selected by the Company, if so requested by the Majority Holders
     or by the managing underwriters of an underwritten offering of Registrable
     Securities, if any, unless the Exchange Securities or the Registrable
     Securities, as the case may be, are already so rated or unless the Company
     has obtained such ratings for its long-term debt securities generally; and

          (w) in the case of the Exchange Offer Registration Statement (i)
     include in the Exchange Offer Registration Statement a section entitled
     "Plan of Distribution," which section shall be reasonably acceptable to the
     Initial Purchasers or another representative of the Participating Broker-
     Dealers, and which shall contain a summary statement of the positions taken
     or policies made by the staff of the SEC with respect to the potential
     "underwriter" status of any broker-dealer (a "Participating Broker-Dealer")
     that holds Registrable Securities acquired for its own account as a result
     of market-making activities or other trading activities and that will be
     the beneficial owner (as defined in Rule 13d-3 under the Exchange Act) of
     Exchange Securities to be received by such broker-dealer in the Exchange
     Offer, whether such positions or policies have been publicly disseminated
     by the staff of the SEC or such positions or policies, in the reasonable
     judgment of the Initial Purchasers or such other representative, represent
     the prevailing views of the staff of the SEC, including a statement that
     any such Participating Broker-Dealer who receives Exchange Securities for
     Registrable Securities pursuant to the Exchange Offer may be deemed a
     statutory underwriter and must deliver a prospectus meeting the
     requirements of the Securities Act in connection with any resale of such
     Exchange Securities, (ii) furnish to each Participating Broker-Dealer who
     has delivered to the Company the notice referred to in Section 3(e),
     without charge, as many copies of each Prospectus included in the Exchange
     Offer Registration Statement, including any preliminary prospectus, and any
     amendment or supplement thereto, as such Participating Broker-Dealer may
     reasonably request (each of the Company and the Trust hereby consents to
     the use of the Prospectus forming part of the Exchange Offer Registration
     Statement or any amendment or supplement thereto by any Person subject to
     the prospectus delivery requirements of the Securities Act, including all
     Participating Broker-Dealers, in connection with the sale or transfer of
     the Exchange Securities covered by the Prospectus or any amendment or
     supplement thereto), (iii) use its reasonable best efforts to keep the
     Exchange Offer Registration Statement effective and to amend and supplement
     the Prospectus contained therein in order to permit such Prospectus to be
     lawfully delivered by all Persons subject to the prospectus delivery
     requirements of the Securities Act for such period of time as such Persons
     must comply with such requirements 

                                      -19-
<PAGE>
 
     under the Securities Act and applicable rules and regulations in order to
     resell the Exchange Securities; provided, however, that such period shall
     not be required to exceed 90 days (or such longer period if extended
     pursuant to the last sentence of Section 3 hereof) (the "Applicable
     Period"), and (iv) include in the transmittal
     letter or similar documentation to be executed by an exchange offeree in
     order to participate in the Exchange Offer (x) the following provision:

          "If the exchange offeree is a broker-dealer holding Registrable
          Securities acquired for its own account as a result of market-making
          activities or other trading activities, it will deliver a prospectus
          meeting the requirements of the Securities Act in connection with any
          resale of Exchange Securities received in respect of such Registrable
          Securities pursuant to the Exchange Offer";

     and (y) a statement to the effect that by a broker-dealer making the
     acknowledgment described in clause (x) and by delivering a Prospectus in
     connection with the exchange of Registrable Securities, the broker-dealer
     will not be deemed to admit that it is an underwriter within the meaning of
     the Securities Act.

          The Company or the Trust may require each seller of Registrable
Securities as to which any registration is being effected to furnish to the
Company or the Trust, as applicable, such information regarding such seller as
may be required by the staff of the SEC to be included in a Registration
Statement.  The Company or the Trust may exclude from such registration the
Regis  trable Securities of any seller who fails to furnish such information
within a reasonable time after receiving such request.  The Company shall have
no obligation to register under the Securities Act the Registrable Securities of
a seller who so fails to furnish such information.

          In the case of a Shelf Registration Statement, or if Participating
Broker-Dealers who have notified the Company and the Trust that they will be
utilizing the Prospectus contained in the Exchange Offer Registration Statement
as provided in Section 3(w) hereof are seeking to sell Exchange Securities and
are required to deliver Prospectuses, each Holder agrees that, upon receipt of
any notice from the Company or the Trust of the happening of any event of the
kind described in Section 3(e)(ii), 3(e)(iii), 3(e)(v) or 3(e)(vi) hereof, such
Holder will forthwith discontinue disposition of Registrable Securities pursuant
to a Registration Statement until such Holder's receipt of the copies of the
supplemented or amended Prospectus contemplated by Section 3(i) hereof or until
it is advised in writing (the "Advice") by the Company and the Trust that the
use of the applicable Prospectus may be resumed, and, if so directed by the
Company and the Trust, such Holder will deliver to the Company or the Trust (at
the Company's or the Trust's expense, as the case requires) all copies in such
Holder's possession, other than permanent file copies then in such Holder's
possession, of the Prospectus covering such Registrable Securities or Exchange
Securities, as the case may be, current at the time of receipt of such notice.
If the Company or the Trust shall give any such notice to suspend the
disposition of Registrable Securities or Exchange Securities, as the case may
be, pursuant to a Registration Statement, the Company and the Trust shall use
their reasonable best efforts to file and have declared effective (if an
amendment) as soon as practicable an amendment or supplement to the Registration
Statement and shall extend the period during which 

                                      -20-
<PAGE>
 
such Registration Statement is required to be maintained effective and usable
for resales pursuant to this Agreement by the number of days in the period from
and including the date of the giving of such notice to and including the date
when the Company and the Trust shall have made available to the Holders (x)
copies of the supplemented or amended Prospectus necessary to resume such
dispositions or (y) the Advice.

          4.   Indemnification and Contribution.  (a) In connection with any
Registration Statement, the Company and the Trust shall, jointly and severally,
indemnify and hold harmless each Initial Purchaser, each Holder, each
underwriter who participates in an offering of the Registrable Securities, each
Participating Broker-Dealer, each Person, if any, who controls any of such
parties within the meaning of Section 15 of the Securities Act or Section 20 of
the Exchange Act and each of their respective directors, officers, employees and
agents, as follows:

          (i)    from and against any and all loss, liability, claim, damage and
     expense whatsoever, joint or several, as incurred, arising out of any
     untrue statement or alleged untrue statement of a material fact contained
     in any Registration Statement (or any amendment thereto) covering
     Registrable Securities or Exchange Securities, including all documents
     incorporated therein by reference, or the omission or alleged omission
     therefrom of a material fact required to be stated therein or necessary to
     make the statements therein not misleading or arising out of any untrue
     statement or alleged untrue statement of a material fact contained in any
     Prospectus (or any amendment or supplement thereto) or the omission or
     alleged omission therefrom of a material fact necessary in order to make
     the statements therein, in the light of the circumstances under which they
     were made, not misleading;

          (ii)   from and against any and all loss, liability, claim, damage and
     expense whatsoever, joint or several, as incurred, to the extent of the
     aggregate amount paid in settlement of any litigation, or any investigation
     or proceeding by any court or governmental agency or body, commenced or
     threatened, or of any claim whatsoever based upon any such untrue statement
     or omission, or any such alleged untrue statement or omission, if such
     settlement is effected with the prior written consent of the Company; and

          (iii)  from and against any and all expenses whatsoever, as incurred
     (including reasonable fees and disbursements of counsel chosen by such
     Holder, such Participating Broker-Dealer, or any underwriter (except to the
     extent otherwise expressly provided in Section 4(c) hereof)), reasonably
     incurred in investigating, preparing or defending against any litigation,
     or any investigation or proceeding by any court or governmental agency or
     body, commenced or threatened, or any claim whatsoever based upon any such
     untrue statement or omission, or any such alleged untrue statement or
     omission, to the extent that any such expense is not paid under
     subparagraph (i) or (ii) of this Section 4(a);

provided, however, that (x) this indemnity does not apply to any loss,
liability, claim, damage or expense to the extent arising out of an untrue
statement or omission or alleged untrue statement or omission made in reliance
upon and in conformity with written information furnished in writing to the
Company or the Trust by such Holder, such Participating Broker-Dealer or any
underwriter with respect to such Holder, Participating Broker-Dealer or any
underwriter, as the case may be, expressly 

                                      -21-
<PAGE>
 
for use in a Registration Statement (or any amendment thereto) or any Prospectus
(or any amendment or supplement thereto) and (y) the Company and the Trust shall
not be liable to any such Holder, Participating Broker Dealer, any underwriter
or controlling person, with respect to any untrue statement or alleged untrue
statement or omission or alleged omission in any preliminary Prospectus to the
extent that any such loss, liability, claim, damage or expense of any Holder,
Participating Broker-Dealer, any underwriter or controlling person results from
the fact that such Holder, any underwriter or Participating Broker-Dealer sold
Securities to a person to whom there was not sent or given, at or prior to the
written confirmation of such sale, a copy of the final Prospectus as then
amended or supplemented if the Company had previously furnished copies thereof
to such Holder, underwriter or Participating Broker-Dealer and the loss,
liability, claim, damage or expense of such Holder, underwriter, Participating
Broker-Dealer or controlling person results from an untrue statement or omission
of a material fact contained in the preliminary Prospectus which was corrected
in the final Prospectus. Any amounts advanced by the Company or the Trust to an
indemnified party pursuant to this Section 4 as a result of such losses shall be
returned to the Company or the Trust if it shall be finally determined by such a
court in a judgment not subject to appeal or final review that such indemnified
party was not entitled to indemnification by the Company or the Trust.

          (b) Each Holder agrees, severally and not jointly, to indemnify and
hold harmless the Company, the Trust, any underwriter and the other selling
Holders and each of their respective directors, officers (including each officer
of the Company and the Trust who signed the Registration Statement), employees
and agents and each Person, if any, who controls the Company, the Trust, any
underwriter or any other selling Holder within the meaning of Section 15 of the
Securities Act or Section 20 of the Exchange Act, from and against any and all
loss, liability, claim, damage and expense whatsoever described in the indemnity
contained in Section 4(a) hereof, as incurred, but only with respect to untrue
statements or omissions, or alleged untrue statements or omissions, made in a
Registration Statement (or any amendment thereto) or any Prospectus (or any
amendment or supplement thereto) in reliance upon and in conformity with written
information furnished to the Company or the Trust by such selling Holder with
respect to such Holder expressly for use in such Registration Statement (or any
amendment thereto), or any such Prospectus (or any amendment or supplement
thereto); provided, however, that, in the case of a Shelf Registration
Statement, no such Holder shall be liable for any claims hereunder in excess of
the amount of net proceeds received by such Holder from the sale of Registrable
Securities pursuant to such Shelf Registration Statement.

          (c) Each indemnified party shall give prompt notice to each
indemnifying party of any action commenced against it in respect of which
indemnity may be sought hereunder, enclosing a copy of all papers properly
served on such indemnified party, but failure to so notify an indemnifying party
shall not relieve such indemnifying party from any liability which it may have
under this Section 4, except to the extent that it is materially prejudiced by
such failure.  An indemnifying party may participate at its own expense in the
defense of such action, or, if it so elects within a reasonable time after
receipt of such notice, assume the defense of any suit brought to enforce any
such claim; but if it so elects to assume the defense, such defense shall be
conducted by counsel chosen by it and approved by the indemnified party or
parties, which approval shall not be unreasonably withheld.  In the event that
an indemnifying party elects to assume the defense of any such suit and retain
such counsel, the indemnified party or parties shall bear the fees and expenses

                                      -22-
<PAGE>
 
of any additional counsel thereafter retained by such indemnified party or
parties; provided, however, that the indemnified party or parties shall have the
right to employ counsel (in addition to local counsel) to represent the
indemnified party or parties who may be subject to liability arising out of any
action in respect of which indemnity may be sought against the indemnifying
party if, in the reasonable judgment of counsel for the indemnified party or
parties, there may be legal defenses available to such indemnified party or
parties which are different from or in addition to those available to the
indemnifying party, in which event the fees and expenses of appropriate separate
counsel shall be borne by the indemnifying party.  In no event shall the
indemnifying parties be liable for the fees and expenses of more than one
counsel (in addition to local counsel), separate from its own counsel, for all
indemnified parties in connection with any one action or separate but similar or
related actions in the same jurisdiction arising out of the same general
allegations or circumstances.  No indemnifying party shall, without the prior
written consent of the indemnified parties, settle or compromise or consent to
the entry of any judgment with respect to any litigation, or any investigation
or proceeding by any governmental agency or body, commenced or threatened, or
any claim whatsoever in respect of which indemnification or contribution could
be sought under this Section 4 (whether or not the indemnified parties are
actual or potential parties thereto), unless such settlement, compromise or
consent (i) includes an unconditional written release in form and substance
satisfactory to the indemnified parties of each indemnified party from all
liability arising out of such litigation, investigation, proceeding or claim and
(ii) does not include a statement as to or an admission of fault, culpability or
a failure to act by or on behalf of any indemnified party.

          (d) In order to provide for just and equitable contribution in
circumstances under which any of the indemnity provisions set forth in this
Section 4 is for any reason held to be unavail  able to the indemnified parties
although applicable in accordance with its terms, the Company, the Trust and the
Holders shall contribute to the aggregate losses, liabilities, claims, damages
and expenses of the nature contemplated by such indemnity agreement incurred by
the Company, the Trust and the Holders, as incurred; provided, that no Person
guilty of fraudulent misrepresentation (within the meaning of Section ll(f) of
the 1933 Act) shall be entitled to contribution from any Person that was not
guilty of such fraudulent misrepresentation.  As between the Company, the Trust
and the Holders, such parties shall contribute to such aggregate losses,
liabilities, claims, damages and expenses of the nature contemplated by such
indemnity agreement in such proportion as shall be appropriate to reflect the
relative fault of the Company and the Trust, on the one hand, and the Holders,
on the other hand, with respect to the statements or omissions which resulted in
such loss, liability, claim, damage or expense, or action in respect thereof, as
well as any other relevant equitable considerations.  The relative fault of the
Company and the Trust, on the one hand, and of the Holders, on the other hand,
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 Company or the
Trust, on the one hand, or by or on behalf of the Holders, on the other hand,
and the parties' relative intent, knowledge, access to information and
opportunity to correct or prevent such statement or omission.  The Company, the
Trust and the Holders of the Registrable Securities agree that it would not be
just and equitable if contribution pursuant to this Section 4 were to be
determined by pro rata allocation or by any other method of allocation that does
not take into account the relevant equitable considerations.  For purposes of
this Section 4, each affiliate of a Holder, and each director, officer,
employee, agent and Person, if any, who controls a Holder or such affiliate
within the meaning of Section 15 of the 

                                      -23-
<PAGE>
 
Securities Act or Section 20 of the Exchange Act shall have the same rights to
contribution as such Holder, and each director of each of the Company or the
Trust, each officer of each of the Company or the Trust who signed the
Registration Statement, and each Person, if any, who controls each of the
Company and the Trust within the meaning of Section 15 of the Securities Act or
Section 20 of the Exchange Act shall have the same rights to contribution as
each of the Company or the Trust.

          5.   Participation in an Underwritten Registration.  No Holder may
participate in an underwritten registration hereunder unless such Holder (a)
agrees to sell such Holder's Registrable Securities on the basis provided in the
underwriting arrangement approved by the Persons entitled hereunder to approve
such arrangements and (b) completes and executes all reasonable questionnaires,
powers of attorney, indemnities, underwriting agreements, lock-up letters and
other documents reasonably required under the terms of such underwriting
arrangements.

          6.   Selection of Underwriters.  The Holders of Registrable Securities
covered by the Shelf Registration Statement who desire to do so may sell the
securities covered by such Shelf Registration in an underwritten offering,
subject to the provisions of Section 3(1) hereof.  In any such underwritten
offering, the underwriter or underwriters and manager or managers that will
administer the offering will be selected by the Holders of a majority in
aggregate principal amount or liquidation amount, as applicable, of the
Registrable Securities included in such offering; provided, however, that such
underwriters and managers must be reasonably satisfactory to the Company and the
Trust.

          7.   Miscellaneous.

          (a) Rule 144 and Rule 144A.  For so long as the Company or the Trust
is subject to the reporting requirements of Section 13 or 15 of the Exchange Act
and any Registrable Securities remain outstanding, each of the Company and the
Trust, as the case may be, will use its reasonable best efforts to file the
reports required to be filed by it under the Securities Act and Section 13(a) or
15(d) of the Exchange Act and the rules and regulations adopted by the SEC
thereunder, provided, that if it ceases to be so required to file such reports,
it will, upon the request of any Holder of Registrable Securities (a) make
publicly available such information as is necessary to permit sales of its
securities pursuant to Rule 144 under the Securities Act, (b) deliver such
information to a prospective purchaser as is necessary to permit sales of its
securities pursuant to Rule 144A under the Securities Act, and (c) take such
further action that is reasonable in the circumstances, in each case, to the
extent required from time to time to enable such Holder to sell its Registrable
Securities without registration under the Securities Act within the limitation
of the exemptions provided by (i) Rule 144 under the Securities Act, as such
rule may be amended from time to time, (ii) Rule 144A under the Securities Act,
as such rule may be amended from time to time, or (iii) any similar rules or
regulations hereafter adopted by the SEC.  Upon the request of any Holder of
Registrable Securities, the Company and the Trust will deliver to such Holder a
written statement as to whether it has complied with such requirements.

          (b) No Inconsistent Agreements.  The Company or the Trust has not
entered into nor will the Company or the Trust on or after the date of this
Agreement enter into any agreement which is inconsistent with the rights granted
to the Holders of Registrable Securities in this 

                                      -24-
<PAGE>
 
Agreement or otherwise conflicts with the provisions hereof. The rights granted
to the Holders hereunder do not in any way conflict with and are not
inconsistent with the rights granted to the holders of the Company's or the
Trust's other issued and outstanding securities under any such agreements.

          (c) Amendments and Waivers.  The provisions of this Agreement,
including the provisions of this sentence, may not be amended, modified or
supplemented, and waivers or consents to departures from the provisions hereof
may not be given unless the Company and the Trust have obtained the written
consent of Holders of at least a majority in aggregate principal amount of the
outstanding Registrable Securities affected by such amendment, modification,
supplement, waiver or departure; provided, that no amendment, modification or
supplement or waiver or consent to the departure with respect to the provisions
of Section 4 hereof shall be effective as against any Holder of Registrable
Securities unless consented to in writing by such Holder of Registrable
Securities. Notwithstanding the foregoing sentence, (i) this Agreement may be
amended, without the consent of any Holder of Registrable Securities, by written
agreement signed by the Company, the Trust and the Initial Purchasers, to cure
any ambiguity, correct or supplement any provision of this Agreement that may be
inconsistent with any other provision of this Agreement or to make any other
provisions with respect to matters or questions arising under this Agreement
which shall not be inconsistent with other provisions of this Agreement, (ii)
this Agreement may be amended, modified or supplemented, and waivers and
consents to departures from the provisions hereof may be given, by written
agreement signed by the Company, the Trust and the Initial Purchasers to the
extent that any such amendment, modification, supplement, waiver or consent is,
in their reasonable judgment, necessary or appropriate to comply with applicable
law (including any interpretation of the staff of the SEC) or any change therein
and (iii) to the extent any provision of this Agreement relates to the Initial
Purchasers, such provision may be amended, modified or supplemented, and waivers
or consents to departures from such provisions may be given, by written
agreement signed by the Initial Purchasers, the Company and the Trust.  Each
Holder of any Registrable Securities then outstanding shall be bound by any
amendment or waiver effected pursuant to this Section 7(c), whether or not any
notice, writing or marking indicating such amendment or waiver appears on such
Registrable Securities or is delivered to such Holder.

          (d) Notices.  All notices and other communications provided for or
permitted hereunder shall be made in writing by hand-delivery, registered first-
class mail, telex, telecopier, or any courier guaranteeing overnight delivery
(i) if to a Holder, at the most current address given by such Holder to the
Company or the Trust by means of a notice given in accordance with the
provisions of this Section 7(d), which address initially is, with respect to the
Initial Purchasers, the address set forth in the Purchase Agreement; and (ii) if
to the Company or the Trust, initially at the Company's address set forth in the
Purchase Agreement and thereafter at such other address, notice of which is
given in accordance with the provisions of this Section 7(d).

          All such notices and communications shall be deemed to have been duly
given:  at the time delivered by hand, if personally delivered; five Business
Days after being deposited in the mail, postage prepaid, if mailed; when
answered back, if telexed; when receipt is acknowledged, if telecopied; and on
the next Business Day, if timely delivered to an air courier guaranteeing
overnight delivery.

                                      -25-
<PAGE>
 
          Copies of all such notices, demands, or other communications shall be
concurrently delivered by the Person giving the same to the Trustee, at the
address specified in the Indenture.

          (e) Successors and Assigns.  This Agreement shall inure to the benefit
of and be binding upon the successors, assigns and transferees of the Initial
Purchasers, including, without limitation, and without the need for an express
assignment, subsequent Holders; provided, however, that nothing herein shall be
deemed to permit any assignment, transfer or other disposition of Registrable
Securities in violation of the terms of the Purchase Agreement or the Indenture.
If any transferee of any Holder shall acquire Registrable Securities, in any
manner, whether by operation of law or otherwise, such Registrable Securities
shall be held subject to all of the terms of this Agreement, and by taking and
holding such Registrable Securities, such Person shall be conclusively deemed to
have agreed to be bound by and to perform all of the terms and provisions of
this Agreement and such Person shall be entitled to receive the benefits hereof.

          (f) Entire Agreement.  This Agreement, the other writings referred to
herein (including the Declaration, the Capital Securities Guarantee and the
Indenture) and the Liquidated Damages Agreement among the parties hereto of even
date contain the entire understandings among the parties with respect to its
subject matter.  This Agreement supersedes all prior agreements and
understandings among the parties with respect to its subject matter.

          (g) Counterparts.  This Agreement may be executed in any number of
counterparts and by the parties hereto in separate counterparts, each of which
when so executed shall be deemed to be an original and all of which taken
together shall constitute one and the same agreement.

          (h) Headings.  The headings in this Agreement are for convenience of
reference only and shall not limit or otherwise affect the meaning hereof.

          (i) GOVERNING LAW.  THIS AGREEMENT SHALL BE DEEMED TO HAVE BEEN MADE
IN THE STATE OF NEW YORK.  THE VALIDITY AND INTERPRETATION OF THIS AGREEMENT,
AND THE TERMS AND CONDITIONS SET FORTH HEREIN, SHALL BE GOVERNED BY AND
CONSTRUED IN ACCORDANCE WITH THE LAWS OF THE STATE OF NEW YORK.

          (j)  Severability.  In the event that any one or more of the
provisions contained herein, or the application thereof in any circumstance, is
held invalid, illegal or unenforceable, the validity, legality and
enforceability of any such provision in every other respect and of the remaining
provisions contained herein shall not be affected or impaired thereby.

          (k)  Securities Held by the Company, the Trust or its Affiliates.
Whenever the consent or approval of the Holders of a specified percentage of
Registrable Securities is required hereunder, Registrable Securities held by the
Company, the Trust or its affiliates (as such term is defined in Rule 405 under
the Securities Act) shall not be counted in determining whether such consent or
approval was given by the Holders of such required percentage.

                                      -26-
<PAGE>
 
              (l)  Limitation of Liability.  The Holders of the Capital
Securities, in their capacities as such, shall not be personally liable for any
liabilities or obligations of the Trust arising out of this Agreement, and the
parties hereto hereby agree that the Holders of the Capital Securities, in their
capacities as such, shall be entitled to the same limitation of personal
liability extended to stockholders of private corporations for profit organized
under the General Corporation Law of the State of Delaware.

                                      -27-
<PAGE>
 
          IN WITNESS WHEREOF, the parties have executed this Agreement as of the
date first written above.


                                    NGC CORPORATION

                                    By:__________________________________
                                    Name:________________________________
                                    Title:_________________________________


                                    NGC CORPORATION CAPITAL TRUST I

                                    By:__________________________________
                                    Name:________________________________
                                    Title:  Administrative Trustee


                                    LEHMAN BROTHERS INC.
                                    SALOMON BROTHERS INC
                                    SMITH BARNEY INC.

                                    By:  LEHMAN BROTHERS INC.


                                    By:___________________________________
                                    Name:________________________________
                                    Title:_________________________________

                                      -28-