<PAGE>
 
                                                                   EXHIBIT 10.20
 
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                        _______________________________



                                XTRA CORPORATION


                        _______________________________



                         REGISTRATION RIGHTS AGREEMENT

                                  by and among

                               XTRA CORPORATION,

                        APOLLO INVESTMENT FUND IV, L.P.,

                        APOLLO OVERSEAS PARTNERS, L.P.,

                           ATLAS CAPITAL PARTNERS LLC

                                      and

                                INTERPOOL, INC.

                        ________________________________



                           Dated as of ____ ___, 1998


                        ________________________________


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

     REGISTRATION RIGHTS AGREEMENT (this "Agreement"), dated as of June __,
1998, by and among XTRA CORPORATION, a Dela  ware corporation (the "Company"),
APOLLO INVESTMENT FUND IV, L.P.,  a Delaware limited partnership ("Apollo
Investment"), APOLLO OVERSEAS PARTNERS IV, L.P., a Cayman Islands limited
partnership ("Apollo Overseas", and, together with Apollo Investment, "Apollo"),
ATLAS CAPITAL PARTNERS LLC, a Dela  ware limited liability company ("Atlas") and
INTERPOOL, INC., a Delaware corporation ("Interpool"), and such other persons to
become parties to this Agreement as described herein.

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

     WHEREAS, pursuant to an Agreement and Plan of Merger and Recapitalization,
dated as of June __, 1998, by and between WHEELS MERGERCO LLC, a Delaware
limited liability company ("MergerCo"), and the Company, MergerCo will be merged
with and into the Company (the "Merger");

     WHEREAS, it is a condition to the obligation of the parties to the Merger
Agreement to consummate the Merger that the parties hereto execute this
Agreement;

     NOW, THEREFORE, in consideration of the mutual agreements and
understandings set forth herein, the parties hereto hereby agree as follows:

     Section  1.  Certain Definitions.  As used in this Agreement, the following
                  -------------------                                           
terms shall have the following respective meanings:

     "Affiliate" means as to any Person (a) any Person which directly or
indirectly controls, is controlled by, or is under common control with such
Person, (b) any Person who is a director, officer, partner or principal of such
Person or of any Person which directly or indirectly controls, is controlled
by, or is under common control with such Person, and (c) any individual who is a
member of the immediate family of any Person described in clause (a) or clause
(b) above. For purposes of this definition, "control" of a Person shall mean the
power, direct or indirect, (i) to vote or direct the voting of 5% or more of the
Voting Stock of such Person or (ii) to direct or cause the direction of the
management 
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and policies of such Person whether by ownership of Capital Stock, by contract
or otherwise.

     "Agreement" means this Agreement as in effect on the date hereof and as
hereafter from time to time amended, modified or supplemented in accordance with
the terms hereof.

     "Board of Directors" means the Board of Directors of the Company as from
time to time hereafter constituted.

     "Capital Stock" means and includes (i) any and all shares, interests,
participations or other equivalents of or interests in (however designated)
corporate stock of any Person, including, without limitation, shares of
preferred or preference stock, (ii) all partnership interests (whether general
or limited) in any Person which is a partnership, (iii) all membership interests
or limited liability company interests in any limited liability company, and
(iv) all equity or ownership interests in any Person of any other type.

     "Commission" means the Securities and Exchange Commission and any
successor commission or agency having similar powers.

     "Common Stock" shall mean the common stock, par value $.50 per share, of
the Company.

     "Exchange Act" means, as of any date, the Securities Exchange Act of 1934,
as amended, or any similar Federal statute then in effect and superseding such
act, and any reference to a particular section thereof shall include a reference
to the comparable section, if any, of such similar Federal statute, and the
rules and regulations thereunder.

     "Fair Market Value" means the fair market value of shares of Common Stock
as determined from time to time by the Board of Directors as evidenced by a
resolution thereof.

     "NASD" means the National Association of Securities Dealers, Inc. and its
successors and assigns.

     "Person" means an individual or a corporation, association, partnership,
limited liability company, joint venture, organization, business, trust or any
other entity or organi-

                                       2
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zation, including a government or any subdivision or agency thereof.

     "Pro Rata Portion" means, with reference to any Shareholder at any time,
a fraction, the numerator of which is the number of shares of Common Stock then
issued and outstanding and held by such Shareholder, and the denominator of
which is the aggregate number of shares of Common Stock then issued and
outstanding and held by the Shareholders taken together.

     "Registrable Securities" means (i) all shares of Common Stock outstanding
on the date hereof and now or hereafter owned of record or beneficially by the
Shareholders, and (ii) any shares of Capital Stock issued by the Company in
respect of any shares of Common Stock referred to in (i) by way of a stock
dividend or stock split or in connection with a combination or subdivision of
shares, reclassification, recapitalization, merger, consolidation or other
reorganization of the Company.  As to any particular Registrable Securities
that have been issued, such securities shall cease to be Registrable Securities
when (i) a registration statement with respect to the sale of such securities
shall have become effective under the Securities Act and such securities shall
have been disposed of under such registration statement, (ii) they shall have
been distributed to the public pursuant to Rule 144 under the Securities Act,
(iii) they shall have been otherwise transferred or disposed of, and new
certificates therefor not bearing a legend restricting further transfer shall
have been delivered by the Company, and subsequent transfer or disposition of
them shall not require their registration or qualification under the Secu
rities Act or any similar state law then in force, (iv) they shall have ceased
to be outstanding, or (v) with respect to the Registrable Securities held by any
Person, when such Registrable Securities, when aggregated with the Registrable
Securities held by such Person's Affiliates, constitute 1% or less of the shares
of Common Stock at the time outstanding.

     "Registration Expenses" shall mean any and all out-of-pocket expenses
incident to the Company's performance of or compliance with Section 2 hereof,
including, without limitation, all Commission, stock exchange and NASD
registration and filing fees, gross underwriting spreads, all fees and expenses
of complying with securities and blue sky laws (including the reasonable fees
and disbursements of under-

                                       3
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writers' counsel in connection with blue sky qualifications and NASD filings),
all fees and expenses of the transfer agent and registrar for the Registrable
Securities, all printing expenses, the fees and disbursements of counsel for the
Company and of its independent public accountants, including the expenses of any
special audits or "cold comfort" letters required by or incident to such
performance and compliance, and one firm of counsel retained by each Shareholder
exercising its rights under Section 5 hereof, but excluding underwriting
discounts and commissions and applicable transfer and documentary stamp taxes,
if any, which shall be borne by the seller of the Registrable Securities in all
cases.

     "Securities Act" means, as of any date, the Securities Act of 1933, as
amended, or any similar Federal statute then in effect and superseding such act,
and any reference to a particular section thereof shall include a reference to
the comparable section, if any, of any such similar Federal statute, and the
rules and regulations thereunder.

     "Shareholder" means, (i) Atlas or Interpool, (ii) Apollo, and (iii) any
other investor in the Company who becomes a party hereto (the "Other
Investors").

     "Subsidiary" means, as to any Person, another Person of which outstanding
Voting Stock having the power to elect a majority of the members of the board of
directors (or comparable body or authority performing similar functions) of
such other Person are at the time owned, directly or indirectly through one or
more intermediaries, or both, by such first Person.

     "Underwritten Offering" means a firm commitment underwriting through a
nationally recognized underwriter.

     "Voting Stock" means Capital Stock of any class or classes, the holders of
which are ordinarily, in the absence of contingencies, entitled to vote for the
election of corporate directors (or Persons performing similar functions).

                                       4
<PAGE>
 
     Section 2.  Registration Rights.
                 ------------------- 

     Section  2.1  Demand Registration.
                   ------------------- 

     (a)  Subject to the conditions and limitations hereinafter set forth in
this Section 2.1, each of the Shareholders may request in writing that the
Company effect the registration under the Securities Act of all or part of such
Shareholder's Registrable Securities specifying in the request the number and
type of Registrable Securities to be registered by such Shareholder and the
intended method of disposition thereof (such notice is hereinafter referred to
as a "Shareholder Request").  A registration requested pursuant to this Section
2.1(a) is referred to herein as a "Demand Registration." Each Shareholder may
request one (or, if Apollo, two) such Demand Registration to be a shelf
registration pursuant to Rule 415 of the Securities Act, with such registration
statement to remain effective for two years; provided that (i) any such demand
shall require the approval of the Board of Directors, unless at the time of such
demand, the Company Common Stock is listed on a na  tional stock exchange or
quoted on the Nasdaq National Market and has a public float of $100 million or
more, and (ii) the existence of such registration shall not affect the
Shareholder's obligations under Sections 2.3(e) and (h). Upon receipt of such
Shareholder Request, the Company will promptly give written notice of such
requested Demand Registration to all other holders of Registrable Securities,
which other holders shall have the right (subject to the limitations set forth
in Section 2.1(f) hereof) to include the Registrable Securities held by them in
such registration and thereupon the Company will, as expeditiously as possible,
use its best efforts to effect the registration under the Securities Act of
the following:

          (i)  the Registrable Securities that the Company has been so requested
     to register by such Shareholder; and

          (ii)  all other Registrable Securities that the Company has been
     requested to register by any other holder thereof by written request given
     to the Company within 10 calendar days after the giving of such written
     notice by the Company (which request shall specify the intended method of
     disposition of such Registrable Securities), all to the extent necessary to
     permit the disposition (in accordance with the intended methods 

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     thereof as aforesaid) of the Registrable Securities so to be registered.

     (b)  Subject to the proviso set forth in Section 2.1(e) hereof, (i) the
Company shall not be obligated to effect more than (A) four Demand Registrations
pursuant to this Section 2.1 at the request of Apollo and (B) two Demand
Registrations pursuant to this Section 2.1 at the request of Interpool or Atlas
and (ii) the Company shall not be obligated to file a registration statement
under Section 2.1(a) hereof unless the Company shall have received requests for
such registration with respect to at least 5% of the outstanding shares of
Common Stock.  In addition, neither Interpool nor Atlas may exercise its rights
under this section to the extent transfers are prohibited under the
Shareholders' Agreement, dated as of June 18, 1998, among Interpool, Atlas,
Apollo, and such other persons to become parties to such agreement as described
therein.

     (c)  The Company shall not be obligated to file a registration statement
relating to any Shareholder Request under Section 2.1(a) hereof within a period
of 6 months after the effective date of any other registration statement filed
by the Company with the Commission.

     (d)  In connection with any offering pursuant to this Section 2.1, the only
shares that may be included in such offering are (i) Registrable Securities and
(ii) shares of authorized but unissued Common Stock that the Company elects to
include in such offering ("Company Securities").

     (e)  If the Board of Directors of the Company makes a good faith
determination, certified by the Chief Executive Officer of the Company, that (i)
the filing of a registration statement or the compliance by the Company with
its disclosure obligations in connection with a registration statement would
require the disclosure of material information that the Company has a bona
                                                                      ----
fide business purpose for preserving as confidential or (ii) such registration
----                                                                          
would be likely to have an adverse affect on any proposal or plan by the Company
to engage in any financing transaction, acquisition of assets (other than in the
ordinary course of business) or any merger, consolidation, tender offer or
similar transaction, the Company may delay the filing of a registration
statement and shall not be required to maintain the effectiveness thereof or
amend or supplement a registra  tion statement for a period expiring upon the
earlier to 

                                       6
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occur of (A) the date on which such material information is disclosed
to the public or ceases to be material, in the case of clause (i), (B) the date
on which such transaction is completed or abandoned, in the case of clause (ii),
or (C) 120 days after the Company makes such good faith determination, in the
case of either clauses (i) or (ii); provided that in such event, the holders of
                                    ---------                                   
Registrable Securities initiating the request for such registration will be 
entitled to withdraw such request, and if such request is withdrawn such
registration will not count as the permitted registration under this Section 2.1
in such event or in any other event, if in the case of any other event, such
holder reimburses the Company for all Registration Expenses relating to such
withdrawn registration.

     (f)  If, in connection with any Underwritten Offering, the managing
underwriter shall advise the Company and any holder of Registrable Securities
that has requested registration that, in its judgment, the number of
securities proposed to be included in such offering should be limited due to
market conditions, the Company will so advise each holder of Registrable
Securities that has requested registration, and shares shall be excluded from
such offering in the following order until such limitation has been met: First,
                                                                         ----- 
the Registrable Securities requested to be included by the Company shall be
excluded until all such Registrable Securities shall have been so excluded; and
thereafter, the Registrable Securities requested to be included in such offering
----------                                                                      
pursuant to Section 2.1(a)(i) hereof by the Shareholder making such request or
pursuant to Section 2.1(a)(ii) hereof by other Shareholders shall be excluded
pro rata, based on the respective number of Registrable Securities as to which
registration has been so requested by such Shareholders, provided, however, that
the Shareholder making such request pursuant to Section 2.1(a)(ii) hereof shall
not be entitled to so register a number of shares greater in proportion to its
total ownership of Registrable Securities than the proportion of shares of
Registrable Securities being registered by the Shareholder requesting
registration pursuant to Section 2.1(a)(i) in relation to that Shareholder's
total ownership of Registrable Securities.

     (g)  A registration requested pursuant to Section 2.1(a) hereof will not be
deemed to have been effected unless it has become effective; provided, that if
                                                             --------         
after it has become effective, the offering of Registrable Securities pursuant
to such registration is interfered with by any stop 

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order, injunction or other order or requirement of the Commission or other
governmental agency or court, such registration will be deemed not to have been
effected.

     (h)  If a Shareholder making a Shareholder Request specifies in the
Shareholder Request an Underwritten Offering, such Shareholder shall have the
right, with the approval of the Company, which approval shall not be
unreasonably withheld, to select the managing underwriter; provided, however, in
                                                           --------  -------
the event that the Company has elected to include Company Securities in such
offering, the Company shall have the right, with the approval of a majority of
the holders of Registrable Securities that have requested to be included in such
offering, which approval shall not be unreasonably withheld, to select the
managing underwriter.

     (i)  The Company will pay all Registration Expenses incurred in connection
with any Demand Registration effected by it pursuant to this Section 2.1.

     Section  2.2  Piggyback Registrations.
                   ----------------------- 

     (a)  If at any time the Company proposes to register any of its equity
securities under the Securities Act (other than a registration on Form S-4 or S-
8 or any successor forms thereto) for the account of another Person or for its
own account, on a form and in a manner that would permit registration of
Registrable Securities for sale to the public under the Securities Act, it will
give written notice to all the holders of Registrable Securities promptly of its
intention to do so, describing such securities and specifying the form and
manner and the other relevant facts involved in such proposed registration,
including, without limitation, (x) the intended method of disposition of the
securities offered, including whether or not such registration will be
effected through an underwriter in an Underwritten Offering or on a "best
efforts" basis, and, in any case, the identity of the managing underwriter, if
any, and (y) the price at which the Registrable Securities are reasonably
expected to be sold.  Upon the written request of any holder of Registrable
Securities delivered to the Company within 30 calendar days after the receipt
of any such notice (which request shall specify the Registrable Securities
intended to be disposed of by such holder), the Company will effect the
registration under the Securities Act of all the Registrable Securities that the
Company has been so requested to register; provided, however, that:
                                           --------  -------       

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<PAGE>
 
          (i)  if, at any time after giving such written notice of its intention
     to register any securities and prior to the effective date of the
     registration statement filed in connection with such registration, the
     Company shall determine for any reason not to register such securities, the
     Company may, at its election, give written notice of such determination to
     each holder of Registrable Securities who shall have made a request for
     registration as hereinabove provided and thereupon the Company shall be
     relieved of its obligation to register any Registrable Securities in
     connection with such registration (but not from its obligation to pay the
     Registration Expenses in connection therewith); and

          (ii  if such registration involves an Underwritten Offering, all
     holders of Registrable Securities requesting to be included in the
     Company's registration must sell their Registrable Securities to the
     underwriters selected by the Company on the same terms and conditions as
     apply to the Company.

     (b)  The Company shall not be obligated to effect any registration of
Registrable Securities under this Section 2.2 incidental to the registration of
any of its securities in connection with mergers, acquisitions, exchange offers,
dividend reinvestment plans or stock option or other employee benefit plans.

     (c)  If a registration pursuant to this Section 2.2 involves an
Underwritten Offering and the managing underwriter advises the issuer that, in
its opinion, the number of securities proposed to be included in such
registration should be limited due to market conditions, the Company will so
advise each holder of Registrable Securities that has requested registration
pursuant to Section 2.2(a) hereof, and shares shall be excluded from such
offering pro rata, based on the respective number of Registrable Securities as
         --- ----                                                             
to which registration has been so requested by such Share  holders, until all
such Registrable Securities shall have been so excluded; and thereafter, the
securities requested to be registered by the Company shall be excluded.

     (d)  In connection with any Underwritten Offering with respect to which
holders of Registrable Securities shall have requested registration pursuant to
this Section 2.2, the Company shall have the right to select the managing
underwriter with respect to the offering; provided that such 
                                          --------                   

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managing underwriter shall be a nationally recognized investment banking firm.

     (e)  The Company will pay all Registration Expenses incurred in connection
with each of the registrations of Registrable Securities effected by it pursuant
to this Section 2.2.

     Section  2.3  Registration Procedures.
                   ----------------------- 

     (a)  If and whenever the Company is required to use its best efforts to
effect or cause the registration of any Registrable Securities under the
Securities Act as provided in Section 2.1 or 2.2 hereof, the Company will, as
expeditiously as possible:

          (i)  prepare and, in any event within 90 calendar days after the end
     of the period within which requests for registration may be given to the
     Company, file with the Commission a registration statement with respect to
     such Registrable Securities and use its best efforts to cause such
     registration statement to become and remain effective; provided, that the
                                                            --------          
     Company may discontinue any registration of its securities that is being 
     effected pursuant to Section 2.2 hereof at any time prior to the effective
     date of the registration statement relating thereto;

          (ii)  prepare and file with the Commission such amendments (including
     post-effective amendments) and supplements to such registration statement
     and the prospectus used in connection therewith as may be necessary to keep
     such registration statement effective for such period as may be requested
     by the Shareholders not exceeding nine months (or two years for a shelf
     registration) and to comply with the provisions of the Securities Act with
     respect to the disposition of all the shares of Common Stock covered by
     such registration statement during such period in accordance with the
     intended methods of disposition by the seller or sellers thereof set
     forth in such registration statement;

          (iii)  furnish to each holder of Registrable Securities covered by the
     registration statement and to each underwriter, if any, of such Registrable
     Securities, such number of copies of a prospectus and preliminary
     prospectus for delivery in conformity with the 

                                       10
<PAGE>
 
     requirements of the Securities Act, and such other documents, as such
     Person may reasonably request, in order to facilitate the public sale or
     other disposition of the Registrable Securities;

          (iv)  use its best efforts to register or qualify such Registrable
     Securities covered by such registration statement under such other
     securities or blue sky laws of such jurisdictions as each seller shall
     reasonably request, and do any and all other acts and things which may be
     reasonably necessary or advisable to enable such seller to consummate the
     disposition of the Registrable Securities owned by such seller in such
     jurisdictions, except that the Company shall not for any such purpose be
     required (A) to qualify to do business as a foreign corporation in any
     jurisdiction where, but for the requirements of this Section 2.3(a)(iv), it
     is not then so qualified, (B) to subject itself to taxation in any such
     jurisdiction, or (C) to take any action which would subject it to general
     or unlimited service of process in any such jurisdiction where it is then
     so subject;

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

          (vi) immediately notify each seller of Registrable Securities
     covered by such registration statement, at any time when a prospectus
     relating thereto is required to be delivered under the Securities Act
     within the appropriate period mentioned in Section 2.3(a)(ii) hereof, if
     the Company becomes aware that the prospectus included in such registration
     statement, as then in effect, includes an untrue statement of a material
     fact or omits to state any material fact required to be stated therein or
     necessary to make the statements therein not misleading in the light of the
     circumstances then existing, and, at the request of any such seller,
     deliver a reasonable number of copies of an amended or supplemental
     prospectus as may be necessary so that, as thereafter delivered to the
     purchasers of such Registrable Securities, such prospectus shall not
     include an untrue statement of a material fact or 

                                       11
<PAGE>
 
     omit to state a material fact required to be stated therein or necessary to
     make the statements therein not misleading in the light of the
     circumstances then existing;

          (vii)  otherwise use its best efforts to comply with all applicable
     rules and regulations of the Commission and make generally available to
     its security holders, in each case as soon as practicable, but not later
     than 45 calendar days after the close of the period covered thereby (90
     calendar days in case the period covered corresponds to a fiscal year of
     the Company), an earnings statement of the Company which will satisfy the
     provisions of Section 11(a) of the Securities Act;

          (viii) use its best efforts in cooperation with the underwriters to
     list such Registrable Securities on each securities exchange on which the
     shares of Common Stock are then listed or, if the shares of Common Stock
     are not then listed on a securities exchange, on each securities exchange
     as the underwriters may reasonably designate;

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

          (x)  in the event such registration is effected through an
     Underwritten Offering, use its best efforts to obtain a "cold comfort"
     letter from the independent public accountants for the Company in customary
     form and covering such matters of the type customarily covered by such
     letters as the holders of Registrable Securities requesting registration
     may reasonably request in order to effect an underwritten public offering
     of such Registrable Securities; and

          (xi)  execute and deliver all instruments and documents (including in
     an Underwritten Offering an underwriting agreement in the form customary
     for such underwriter) and take such other actions and obtain such
     certificates and opinions as the holders of Registrable Securities
     requesting registration may reasonably request in order to effect an
     underwritten public offering of such Registrable Securities.

                                       12
<PAGE>
 
     (b)  It shall be a condition precedent to the obligation of the Company
to take any action pursuant to this Section 2 in respect of Registrable
Securities that each holder requesting registration thereof shall furnish to the
Company such information regarding the Registrable Securities held by such
holder and the intended method of disposition thereof as the Company shall
reasonably request and as shall be required in connection with the action taken
by the Company; provided, however, that the failure of any holder of Registrable
                --------  -------                                               
Securities to furnish such information shall not affect the obligations of the
Company pursuant to this Section 2 with respect to any holder of Registrable
Securities who furnishes such information to the Company.  Notwithstanding
any provision to the contrary contained herein, no holder of Registrable
Securities shall be required (i) to furnish any information to the Company or
the underwriters in connection with such registration, other than in a writing
furnished by such holder expressly for use in such registration statement which
shall be limited to matters concerning such holder's identity, its beneficial
ownership of securities of the Company, the class and number of such securities
it intends to include in such registration and its intended method of
distribution, or (ii) to make any representations or warranties to the Company,
the underwriters or any other Person (whether in the underwriting agreement
or otherwise), except with respect to the information so furnished.

     (c)  Each holder of Registrable Securities will, upon receipt of any notice
from the Company of the happening of any event of the kind described in Section
2.3(a)(vi) hereof, forthwith discontinue disposition of the Registrable
Securities pursuant to the registration statement covering such Registrable
Securities until such holder's receipt of the copies of the supplemented or
amended prospectus contemplated by Section 2.3(a)(vi) hereof.

     (d)  If a registration pursuant to Section 2.1 or 2.2 hereof involves an
Underwritten Offering, each holder of Registrable Securities agrees, whether or
not such holder's Registrable Securities are included in such registration, not
to effect any sale or distribution, including any sale pursuant to Rule 144
under the Securities Act, of any Registrable Securities, or of any security
convertible into or exchangeable or exercisable for any Registrable Securities
(other than as part of such Underwritten Offering), without the consent of the
managing underwriter, during a period 

                                       13
<PAGE>
 
commencing seven calendar days before and ending 180 calendar days (or such
lesser number as the managing underwriter shall designate) after the effective
date of such registration; provided, that such period shall not extend beyond
                           --------
the period during which the Company is subject to such a restriction.

     (e)  If a registration pursuant to Section 2.1 or 2.2 hereof involves an
Underwritten Offering, the Company agrees, if so required by the managing
underwriter, not to effect any sale or distribution of any of its equity or debt
securities, as the case may be, or securities convertible into or exchangeable
or exercisable for any of such equity or debt securities, as the case may be,
during a period commencing seven calendar days before and ending 180 calendar
days after the effective date of such registration, except for such Underwritten
Offering or except in connection with a stock option plan, stock purchase
plan, savings or similar plan, or an acquisition, merger or exchange offer.

     (f)  If a registration pursuant to Section 2.1 or 2.2 hereof involves an
Underwritten Offering, any holder of Registrable Securities requesting to be
included in such registration may elect, in writing, not less than five days
prior to the effective date of the registration statement filed in connection
with such registration, not to register such securities in connection with such
registration, unless such holder has agreed with the Company or the managing
underwriter to limit its rights under this Section 2.3.

     (g)  It is understood that in any Underwritten Offering in addition to any
shares of Common Stock (the "initial shares") the underwriters have committed to
purchase, the underwriting agreement may grant the underwriters an option to
purchase up to a number of additional authorized but unissued shares of Common
Stock (the "option shares") equal to 15% of the initial shares (or such other
maximum amount as the NASD may then permit), solely to cover over-allotments.
Shares of Common Stock proposed to be sold by the Company and the other sellers
shall be allocated between initial shares and option shares as agreed or, in the
absence of agreement, pursuant to Section 2.1(f) or 2.2(c) hereof, as the case
may be.  The number of initial shares and option shares to be sold by requesting
holders shall be allocated pro rata among all such holders on the basis of the
                           --- ----                                           
relative number of shares of Registrable Securities each 

                                       14
<PAGE>
 
such holder has requested to be included in such registration.

     (h)  If the Company shall notify pursuant to Section 2.3(a)(iv) any
Shareholder for whom a shelf registration statement has been filed and remains
effective, such Shareholder shall suspend use of such registration statement
until an appropriate prospectus supplement has been prepared and filed with the
Commission; it being understood that the Company shall make all reasonable
efforts to ensure that the time period for which use of the registration
statement is suspended does not exceed 90 days in any 12 month period.

     Section  2.4  Indemnification.
                   --------------- 

     (a) In the event of any registration of any securities under the Securities
Act pursuant to Section 2.1 or 2.2 hereof, the Company will, and it hereby
agrees to, indemnify and hold harmless, to the extent permitted by law, each
seller of any Registrable Securities covered by such registration statement,
its directors, officers, employees and agents, each Person who participates as
an underwriter in the offering or sale of such securities and each other Person,
if any, who controls such seller or underwriter within the meaning of the
Securities Act, as follows:

          (i)  against any and all loss, liability, claim, damage or expense
     whatsoever arising out of or based upon an untrue statement or alleged
     untrue statement of a material fact contained in any registration statement
     (or any amendment or supplement thereto), 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 an untrue
     statement or alleged untrue statement of a material fact contained in any
     preliminary prospectus or 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 not misleading;

          (ii) against any and all loss, liability, claim, damage and expense
     whatsoever to the extent of the aggregate amount paid in settlement of any
     litigation, or investigation or proceeding by any governmental agency or
     body, commenced or threatened, or of any 

                                       15
<PAGE>
 
     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 written consent of the Company; and

          (iii) against any and all expense reasonably incurred by them in
     connection with investigating, preparing or defending against any
     litigation, or investigation or proceeding by any 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 clauses (i)
     or (ii) above;

provided, however, that this indemnity does not apply to any loss, liability,
--------  -------                                                            
claim, damage or expense to the extent arising out of an untrue statement or
alleged untrue statement or omission or alleged omission made in reliance upon
and in conformity with written information furnished to the Company by or on
behalf of any such seller or underwriter specifically stating that it is for use
in the preparation of any registration statement (or any amendment thereto) or
any preliminary prospectus or prospectus (or any amendment or supplement
thereto); and provided, further, that the Company will not be liable (A) in the
              --------  -------                                                
case of any Underwritten Offering, to any Person who participates as an 
underwriter in the offering or sale of Registrable Securities or any other
Person, if any, who controls such underwriter within the meaning of the
Securities Act, or (B) in the case of any offering other than an Underwritten
Offering, to any seller of Registrable Securities covered by such registration
statement or any other Person, if any, who controls such seller within the
meaning of the Securities Act, under the indemnity agreement in this Section
2.4(a) with respect to any preliminary prospectus or final prospectus or final
prospectus as amended or supplemented, as the case may be, to the extent that
any such loss, claim, damage or liability of such underwriter or controlling
Person (or seller or controlling Person, as the case may be) results from the
fact that such underwriter (or seller, as the case may be) sold Registrable
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 or of the
final prospectus as then amended or supplemented, whichever is most recent, if
the Company has previously furnished copies thereof to such underwriter. Such
indemnity shall remain in

                                       16
<PAGE>
 
full force and effect regardless of any investigation made by or on behalf of
such seller, director, officer, employee, agent, underwriter or controlling
Person, and shall survive the transfer of such securities by such seller.

     (b)  The Company may require, as a condition to including any Registrable
Securities in any registration statement filed in accordance with Section 2.1 or
2.2 hereof, that the Company shall have received an undertaking reasonably 
satisfactory to it from the prospective seller of such Registrable Securities or
any underwriter, to indemnify and hold harmless (in the same manner and to the
same extent as set forth in Section 2.4(a) hereof) the Company and its 
directors and officers and each other Person, if any, who controls the Company
within the meaning of the Securities Act, with respect to any statement or
alleged statement in or omission or alleged omission from such registration
statement, any preliminary, final or summary prospectus contained therein, or
any such amendment or supplement, if such statement or alleged statement or
omission or alleged omission was made in reliance upon and in conformity with
written information furnished to the Company by or on behalf of such seller or
underwriter specifically stating that it is for use in the preparation of such
registration statement, preliminary, final or summary prospectus or amendment or
supplement; provided, however, that the maximum liability of any seller of
            --------  -------                                             
Registrable Securities for such indemnification shall not exceed the net
proceeds received by such seller from the sale of such Registrable Securities.
Such indemnity shall remain in full force and effect regardless of any
investigation made by or on behalf of the Company or any such director, officer
or controlling Person and shall survive the transfer of such securities by such
seller.

     (c)  Promptly after receipt by an indemnified party hereunder of written
notice of the commencement of any action or proceeding involving a claim
referred to in this Section 2.4, such indemnified party will, if a claim in
respect thereof is to be made against an indemnifying party, give written notice
to such indemnifying party of the commencement of such action; provided,
                                                               -------- 
however, that the failure of any indemnified party to give notice as provided
-------                                                                       
herein shall not relieve the indemnifying party of its obligations under this
Section 2.4, except to the extent (not including any such notice of an
underwriter) that the indemnifying party is actually prejudiced by such failure
to give notice.  In case any such action is brought against an 

                                       17
<PAGE>
 
indemnified party, unless in such indemnified party's reasonable judgment a
conflict of interest between such indemnified and indemnifying parties may
exist in respect of such claim (in which case the indemnifying party shall not
be liable for the fees and expenses of more than one counsel for the sellers of
Registrable Securities or for more than one counsel for the underwriters in
connection with any one action or separate but similar or related actions), the
indemnifying party will be entitled to participate in and to assume the defense
thereof, jointly with any other indemnifying party similarly notified, to the
extent that it may wish, with counsel reasonably satisfactory to such 
indemnified party, and after notice from the indemnifying party to such
indemnified party of its election so to assume the defense thereof, the
indemnifying party will not be liable to such indemnified party for any legal or
other expenses subsequently incurred by such indemnified party in connection
with the defense thereof.

     (d)  The Company and each seller of Registrable Securities shall provide
for the foregoing indemnity (with appropriate modifications) in any
underwriting agreement with respect to any required registration or other
qualification of securities under any federal or state law or regulation of any
governmental authority.  The foregoing shall not limit the Company's obligations
under Section 2.3(a)(xi).

     Section  2.5  Contribution.  In order to provide for just and equitable
                   ------------                                             
contribution in circumstances under which the indemnity contemplated by Section
2.4 hereof is for any reason not available, the parties required to indemnify by
the terms thereof shall contribute to the aggregate losses, liabilities, claims,
damages and expenses of the nature contemplated by such indemnity agreement
incurred by the Company, any seller of Registrable Securities and one or more of
the underwriters, except to the extent that contribution is not permitted
under Section 11(f) of the Securities Act.  In determining the amounts that
the respective parties shall contribute, there shall be considered the relative
benefits received by each party from the offering of the Registrable Securities
(taking into account the portion of the proceeds of the offering realized by
each), the parties' relative knowledge and access to information concerning the
matter with respect to which the claim was asserted, the opportunity to correct
and prevent any statement or omission and any other equitable considerations
appropriate under the circumstances.  The Company and each 

                                       18
<PAGE>
 
Person selling securities agree with each other that no seller of Registrable 
Securities shall be required to contribute any amount in excess of the amount
such seller would have been required to pay to an indemnified party if the
indemnity under Section 2.4 hereof were available. The Company and each such
seller agree with each other and the underwriters of the Registrable Securities,
if requested by such underwriters, that it would not be equitable if the amount
of such contribution were determined by pro rata or per capita allocation (even
                                        --- ----
if the underwriters were treated as one entity for such purpose) or for the
underwriters' portion of such contribution to exceed the percentage that the
underwriting discount bears to the public offering price of the Registrable
Securities. For purposes of this Section 2.5, each Person, if any, who controls
an underwriter within the meaning of the Securities Act shall have the same
rights to contribution as such underwriter, and each director and each officer
of the Company who signed the registration statement, and each Person, if any,
who controls the Company or a seller of Registrable Securities, shall have the
same rights to contribution as the Company or a seller of Registrable
Securities, as the case may be.

     Section  2.6  Rule 144.  If the Company shall have filed a registration
                   --------                                                 
statement pursuant to the requirements of Section 12 of the Exchange Act or a
registration statement pursuant to the requirements of the Securities Act, the
Company covenants that it will file the reports required to be filed by it under
the Securities Act and the Exchange Act and the rules and regulations adopted by
the Commission thereunder (or, if the Company is not required to file such
reports, it will, upon the request of any holder of Registrable Securities,
make publicly available other information), and it will take such further
action as any holder of Registrable Securities may reasonably request, all to
the extent required from time to time to enable such holder to sell shares of
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 or (ii) any similar rule or
regulation hereafter adopted by the Commission.  Upon the request of any
holder of Registrable Securities, the Company will deliver to such holder a
written statement as to whether the Company has complied with such requirements.

      Section 3.  Miscellaneous.
                  ------------- 

                                       19
<PAGE>
 
     Section  3.1   Successors and Assigns.  Except as otherwise provided
                    ----------------------                                
herein, all the terms and provisions of this Agreement shall be binding upon,
shall inure to the benefit of and shall be enforceable by the respective
successors and assigns of the parties hereto.  No Shareholder may assign any of
its rights hereunder to any Person other than a transferee that has complied in
all respects with the requirements of this Agreement.  The Company may not
assign any of its rights hereunder to any other Person.  If any transferee of
any Shareholder shall acquire any shares of Common Stock in any manner, whether
by operation of law or otherwise, such shares shall be held subject to all of
the terms of this Agreement, and by taking and holding such shares such Person
shall be entitled to receive the benefits of and be conclusively deemed to have
agreed to be bound by and to comply with all of the terms and provisions of this
Agreement.

     Section  3.2  Amendment and Modification; Waiver of Compliances; Conflicts.
                   ------------------------------------------------------------ 

     (a)  This Agreement may be amended only by a written instrument duly
executed by all of the Shareholders and the Company.

     (b)  Except as otherwise provided in this Agreement, any failure of any of
the parties to comply with any obligation, covenant, agreement or condition
herein may be waived by the party entitled to the benefits thereof only by a
written instrument signed by the party granting such waiver, but such waiver or
failure to insist upon strict compliance with such obligation, covenant,
agreement or condition shall not operate as a waiver of, or estoppel with
respect to, any subsequent or other failure.

     (c)  In the event of any conflict between the provisions of this
Agreement and the provisions of any other agreement, the provisions of this
Agreement shall govern and prevail.

     Section  3.3  Notices.  All notices and other communications provided for
                   -------                                                     
hereunder shall be in writing and delivered by hand or sent by first class mail
or sent by telecopy (with such telecopy to be confirmed promptly in writing sent
by first class mail), sent as follows:

                                       20
<PAGE>
 
          (i)  If to the Company, addressed to:

               c/o XTRA Corporation
               [Address]
               [Address]
               Attention:[
               Telecopy:[   ]

          with a copy to:

               Ropes & Gray
               One International Place
               Boston, MA 02110
               Attention:  David A. Fine, Esq.
               Telecopy: (617) 951-7050


          (ii)  If to Apollo, addressed to:

               c/o Apollo Management IV, L.P.
               1301 Avenue of the Americas
               38th Floor
               New York, New York  10019
               Attention:  Michael S. Gross
               Telecopy:  (212) 261-4071

          with a copy to:

               Skadden, Arps, Slate, Meagher & Flom LLP
               919 Third Avenue
               New York, New York  10022
               Attention:  David J. Friedman, Esq.
               Telecopy:  (212) 735-2000

          (iii)  If to Interpool or Atlas, addressed to:

               Interpool, Inc.
               635 Third Avenue
               New York, New York  10017
               Attention:  Martin Tuchman
               Telecopy:   (212) 687-8403

               Atlas Capital Partners
               633 Third Avenue
               New York, New York  10017
               Attention:  Mitchell I. Gordon
               Telecopy:  (212) 916-3284

                                       21
<PAGE>
 
          with a copy to:

               Camhy Karlinsky & Stein LLP
               1740 Broadway
               New York, New York
               Attention:  Daniel DeWolf, Esq.
               Telecopy:  (212) 977-8389


or to such other address or addresses or telecopy number or numbers as any of
the parties hereto may most recently have designated in writing to the other
parties hereto by such notice.  All such communications shall be deemed to have
been given or made when so delivered by hand or sent by telecopy, or three
business days after being so mailed.

     Section  3.4  Entire Agreement; Governing Law.
                   ------------------------------- 

     (a)  This Agreement and the other writings referred to herein or delivered
pursuant hereto which form a part hereof contain the entire agreement among the
parties hereto with respect to the subject transactions contemplated hereby and
supersede all prior oral and written agreements and memoranda and undertakings
among the parties hereto with regard to this subject matter.  The Company
represents to the Share  holders that the rights granted to the holders
hereunder do not in any way conflict with and are not inconsistent with the
rights granted or obligations accepted under any other agreement (including its
Certificate of Incorporation) to which the Company is a party.  Neither the
Company nor any Subsidiary of the Company will hereafter enter into any
agreement with respect to its equity or debt securities which is inconsistent
with the rights granted to any Shareholder under this Agreement without
obtaining the prior written consent of the Shareholder.

     (B)  THIS AGREEMENT SHALL BE GOVERNED BY AND CONSTRUED IN ACCORDANCE WITH
THE LAWS OF THE STATE OF DELAWARE (WITHOUT GIVING EFFECT TO THE CHOICE OF LAW
PRINCIPLES THEREOF).

     Section  3.5  Injunctive Relief.  The Shareholders acknowledge and agree
                   -----------------                                         
that a violation of any of the terms of this Agreement will cause the
Shareholders irreparable injury for which an adequate remedy at law is not
available. Therefore, the Shareholders agree that each Shareholder shall be
entitled to, an injunction, restraining order or 

                                       22
<PAGE>
 
other equitable relief from any court of competent jurisdiction, restraining
any Shareholder from committing any violations of the provisions of this
Agreement.

     Section  3.6  Availability of Agreement.  For so long as this Agreement
                   -------------------------                                
shall be in effect, this Agreement shall be made available for inspection by any
Shareholder upon request at the principal executive offices of the Company.

     Section  3.7  Headings.  The section and paragraph headings contained in
                   --------                                                  
this Agreement are for reference purposes only and shall not affect in any way
the meaning or interpretation of this Agreement.

     Section  3.8  Recapitalizations, Exchanges, Etc. Affecting the Shares of
                   -----------------------------------------------------------
Common Stock; New Issuances.  The provisions of this Agreement shall apply, to
---------------------------                                                   
the full extent set forth herein with respect to the shares of  Common Stock and
to any and all equity or debt securities of the Company or any successor or
assign of the Company (whether by merger, consolidation, sale of assets, or
otherwise) which may be issued in respect of, in exchange for, or in
substitution of, such equity or debt securities and shall be appropriately
adjusted for any stock dividends, splits, reverse splits, combinations,
reclassifications, recapitalizations, reorganizations and the like occurring
after the date hereof.

     Section  3.9  Counterparts.  This Agreement may be executed in two or more
                   ------------                                                
counterparts, each of which shall be deemed an original, but all of which
together shall constitute one and the same instrument.

     Section 3.10.  Effective Date.  This Agreement will become effective upon,
                    --------------                                             
but only upon, consummation of the Merger.

                                       23
<PAGE>
 
     IN WITNESS WHEREOF, the parties hereto have caused this Agreement to be
duly executed as of the date first above written.


                         XTRA CORPORATION



                         By:__________________________
                            Name:
                            Title:



                         APOLLO MANAGEMENT IV, L.P., on behalf of Apollo
                         Investment and Apollo Overseas



                         By:___________________________
                            Name:
                            Title:



                         INTERPOOL, INC.



                         By:___________________________
                            Name:
                            Title:


                         ATLAS CAPITAL PARTNERS LLC



                         By:___________________________
                            Name:
                            Title:

                                       24
<PAGE>
 
                               TABLE OF CONTENTS
                            (Not Part of Agreement)

Section                       Heading                                    Page 
-------                       -------                                    ---- 

1.  Certain Definitions..................................................  1

2.  Registration Rights..................................................  4
    2.1.  Demand Registration............................................  4
    2.2.  Piggyback Registrations........................................  8
    2.3.  Registration Procedures........................................  9
    2.4.  Indemnification................................................ 14
    2.5.  Contribution................................................... 18
    2.6.  Rule 144....................................................... 19

3.  Miscellaneous........................................................ 19
    3.1.  Successors and Assigns......................................... 19
    3.2.  Amendment and Modification: Waiver of Compliances; Conflicts... 20
    3.3.  Notices........................................................ 20
    3.4.  Entire Agreement: Governing Law................................ 22
    3.5.  Injunctive Relief.............................................. 22
    3.6.  Availability of Agreement...................................... 22
    3.7.  Headings....................................................... 22
    3.8. Recapitalizations, Exchanges, Etc. Affecting the Shares of 
           Common Stock; New Issuances................................... 23
    3.9.  Counterparts................................................... 23
    3.10. Effective Date................................................. 23