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                                                                   Exhibit 10.15

                            SALT HOLDINGS CORPORATION
                              AMENDED AND RESTATED
                             STOCK RIGHTS AGREEMENT

                  This Amended and Restated Stock Rights Agreement ("AGREEMENT")
is entered into as of June 23, 2003 by and among Salt Holdings Corporation, a
Delaware corporation (the "COMPANY"), Apollo Management V L.P., a Delaware
limited partnership ("APOLLO MANAGEMENT"), each of the stockholders of the
Company listed on Schedule A attached hereto (such listed stockholders
collectively and together with Apollo Management referred to as the "APOLLO
INVESTORS") and IMC Global Inc., a Delaware corporation ("IMC GLOBAL" and
together with the Apollo Investors, the "INITIAL STOCKHOLDERS").

                                    RECITALS

                  WHEREAS, the Parties are each parties to that certain Stock
Rights Agreement, dated as of November 28, 2001 (the "ORIGINAL STOCK RIGHTS
AGREEMENT");

                  WHEREAS, the Company and IMC Global are each parties to that
certain Escrow Rights Purchase Agreement, dated the date hereof, pursuant to
which IMC Global has agreed to sell, and the Company has agreed to purchase, all
of the right, title and interest of IMC Global in and to that certain Escrow
Agreement entered into in connection with and pursuant to the Original Stock
Rights Agreement and in and to all of the property held thereunder;

                  WHEREAS, in connection with and to effectuate the transactions
contemplated by the Escrow Rights Purchase Agreement, the Parties desire to
amend and restate the Original Stock Rights Agreement as set forth herein to
provide for certain matters with respect to the ownership and transfer of
Securities now held of record or beneficially by, or hereafter acquired by, any
Stockholder.

                                    AGREEMENT

                  NOW, THEREFORE, in consideration of the foregoing, and the
mutual agreements set forth herein and other good and valuable consideration,
the receipt and adequacy of which is hereby acknowledged, the Parties hereto,
intending to be legally bound, hereby agree as follows:

SECTION 1 DEFINITIONS:

        1.1       As used in this Agreement, the following terms have the
following meanings:

                  "APOLLO AFFILIATE" means Apollo Management and its affiliates,
including the Apollo Investors, other than any affiliate that is a portfolio
company of any investment fund that is an affiliate of Apollo Management.

                  "APOLLO COMMON STOCK" means the shares of Common Stock
received by the Apollo Investors pursuant to the Merger Agreement, including any
shares of Common Stock held by the Apollo Investors immediately after the
Closing, and any shares of Capital Stock

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received in distribution thereon or as the result of any stock split, reverse
stock split or recapitalization or in exchange for the Apollo Common Stock.

                  "APOLLO PREFERRED STOCK" means the shares of Preferred Stock
received by the Apollo Investors pursuant to the Merger Agreement, including any
shares of Preferred Stock held by the Apollo Investors immediately after the
Closing, and any debt securities of the Company or shares of Capital Stock
received in distribution thereon or as the result of any stock split, reverse
stock split or recapitalization or in exchange for the Apollo Preferred Stock.

                  "APOLLO STOCKHOLDERS" means any of the Apollo Investors or any
successor thereto. In the event that any Apollo Investor distributes its
Securities to its investors or to any of its affiliates, then Apollo
Stockholders shall include such distributees.

                  "BOARD OF DIRECTORS" means the board of directors of the
Company.

                  "BUSINESS DAY" means any day that is not a Saturday, a Sunday
or other day on which banks are required or authorized by law to be closed in
New York, New York.

                  "CAPITAL STOCK" means any and all shares of capital stock or
any other interest participation that confers on a Person the right to receive a
share of the profits and losses of, or distributions of assets of, the Person
issuing such capital stock or other interest participation.

                  "CLOSING" means the date that the Merger occurs.

                  "COMMON STOCK" means the Class A common stock, par value $0.01
per share, of the Company, or if the Common Stock is no longer outstanding, the
class of Capital Stock issued in exchange for, or in lieu of, Common Stock.

                  "COMPANY SALE" means any transaction or series of transactions
as a result of which one or more Persons acting as a group (other than any
Apollo Affiliate or IMC Stockholder or any affiliate of any IMC Stockholder)
acquires (i) equity securities of the Company constituting greater than fifty
percent (50%) of the Company's voting Common Stock (whether such transaction is
effected by merger, consolidation, recapitalization, sale or transfer of the
Company's equity or otherwise) or (ii) all or substantially all of the assets of
the Company and its subsidiaries.

                  "IMC REGISTERED STOCK" means the 357,000 shares of Common
Stock received by and registered in the name of IMC Global pursuant to the
Merger Agreement that are not subject to the terms and conditions of this
Agreement, and any shares of Common Stock received in distribution thereon or as
the result of any stock split, reverse stock split or recapitalization or in
exchange for IMC Registered Stock.

                  "IMC STOCKHOLDER" means IMC Global.

                  "IPO DATE" means the date on which the Company consummates a
Qualified Public Offering.


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                  "MANAGEMENT CONSULTING AGREEMENT" means that certain
Management Consulting Agreement dated as of November 28, 2001, by and between
the Company and Apollo Management, substantially consistent with the form
attached as EXHIBIT 1.1(Q) to the YBR Holdings LLC Disclosure Letter attached to
the Merger Agreement.

                  "MERGER" means the merger of YBR Acquisition Corp., a Delaware
corporation, into the Company pursuant to the Merger Agreement.

                  "MERGER AGREEMENT" means that certain Agreement and Plan of
Merger dated as of October 13, 2001 among IMC Global, the Company, YBR Holdings
and YBR Acquisition Corp.

                  "NOTE SECURITIES" means the debt securities, if any, to be
issued by the Company in exchange for the Preferred Stock, and any notes or
other Securities received in distribution thereon or in exchange therefor.

                  "PARTIES" means the Stockholders and the Company.

                  "PERSON" means any natural person, corporation, limited
partnership, general partnership, limited liability company, joint stock
company, joint venture, association, company, trust or other organization, or
any governmental authority.

                  "PRE-EMPTIVE PERCENTAGE" means, at any time, as to each IMC
Stockholder, the quotient obtained (expressed as a percentage) by dividing (i)
the number of shares of IMC Registered Stock held by such IMC Stockholder by
(ii) the total number of shares of Common Stock issued and outstanding on the
date of determination.

                  "PREFERRED STOCK" means the Series A Redeemable Exchangeable
Preferred Stock, par value $0.01 per share, of the Company, or if the Preferred
Stock is no longer outstanding, the Note Securities or other debt securities of
the Company or the class of Capital Stock issued in exchange for, or in lieu of,
Preferred Stock.

                  "QUALIFIED PUBLIC OFFERING" means an underwritten public
offering of Common Stock by the Company pursuant to an effective registration
statement filed by the Company with the Securities and Exchange Commission
(other than on Forms S-4 or S-8 or successors to such forms) under the
Securities Act, after which, cumulatively, more than twenty percent (20%) of the
Company has been sold to the public in one or more registered offerings.

                  "REGISTRABLE COMMON STOCK" means all shares of Common Stock,
whether or not issued pursuant to the Merger Agreement and however and whenever
obtained, beneficially owned, or owned of record, by any Apollo Stockholder or
any IMC Stockholder.

                  "SECURITIES" means the Common Stock, the Preferred Stock and
the IMC Notes.

                  "SECURITIES ACT" means the Securities Act of 1933, as amended.

                  "STOCKHOLDERS" means the IMC Stockholders and the Apollo
Stockholders.


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                  "THIRD PARTY PURCHASER" means any Person other than a
Stockholder or their Permitted Transferees who purchases or intends to purchase
Common Stock from any Stockholder or their Permitted Transferees.

                  "TRANSFER" means, sell, transfer, convey, assign, pledge,
hypothecate or otherwise dispose of.

                  (a) The following terms have the meanings defined for such
terms in the Sections set forth below:

                  TERM                                                   SECTION
                  --------------------------------------------------------------
                  Apollo Investors                                      Preamble
                  Apollo Management                                     Preamble
                  Agreement                                             Preamble
                  Bring-Along Notice                                           2
                  Bring-Along Right                                            2
                  Commission                                                 6.3
                  Company                                               Preamble
                  Demand Notice                                              4.1
                  IMC Global                                            Preamble
                  Initial Stockholders                                  Preamble
                  Other Registering Holders                                    5
                  Primary Registration                                         5
                  Prospectus                                                 6.3
                  Registering Stockholder                                      5
                  Registration Statement                                     6.3
                  Request Notice                                             4.1
                  Requesting Stockholder                                     4.1
                  Sale Notice                                                  3
                  Secondary Registration                                       5
                  Tag-Along Stockholders                                       3
                  Tag-Along Notice                                             3
                  Tag-Along Right                                              3
                  Third Party Terms                                            2

                  (b) Unless the context of this Agreement otherwise requires,
(i) words of any gender include each other gender; (ii) words using the singular
or plural number also include the plural or singular number, respectively; (iii)
the terms "hereof," "herein," "hereby" and derivative or similar words refer to
this entire Agreement; (iv) the term "Section" refers to the specified Section
of this Agreement; (v) the word "including" shall mean "including, without
limitation", and (vi) the word "or" shall be disjunctive but not exclusive.

                  (c) References to agreements and other documents shall be
deemed to include all subsequent amendments and other modifications thereto.


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                  (d) References to statutes shall include all regulations
promulgated thereunder and references to statutes or regulations shall be
construed as including all statutory and regulatory provisions consolidating,
amending or replacing the statute or regulation.

                  (e) The language used in this Agreement shall be deemed to be
the language chosen by the Parties to express their mutual intent, and no rule
of strict construction shall be applied against either Party.

SECTION 2 BRING-ALONG RIGHTS

                  In the event that, at any time after the date hereof, one or
more of the Apollo Stockholders, in one transaction or a series of related
transactions that constitute a Company Sale, proposes to Transfer all or any
portion of the Common Stock then held by such Apollo Stockholder to any Third
Party Purchasers (other than Apollo Affiliates), then such Apollo Stockholder
shall have the right (a "BRING-ALONG RIGHT"), but not the obligation, to cause
any of the other Stockholders to tender for purchase to the Third Party
Purchaser, a number of shares of Common Stock equaling the amount derived by
multiplying (i) the total number of shares of Common Stock held by such
Stockholder, by (ii) a fraction, the numerator of which is the total number of
shares of Common Stock to be Transferred by such Apollo Stockholder in
connection with such Company Sale and the denominator of which is the total
number of the then outstanding shares of Common Stock held by all Apollo
Stockholders. If any IMC Stockholder is required to transfer shares of Common
Stock pursuant to this SECTION 2, references to "Common Stock" shall mean "IMC
Registered Stock" with respect to such IMC Stockholder. Following a Company
Sale, one or more of the Apollo Stockholders shall be entitled to exercise a
Bring-Along Right in the event such Apollo Stockholder, in one transaction or a
series of related transactions, proposes to Transfer twenty percent (20%) or
more of the Common Stock then held by such Apollo Stockholder to any Third Party
Purchasers and such Bring-Along Right shall be governed by this SECTION 2 in the
same manner as if the event triggering the right to exercise such Bring-Along
Right were a Company Sale.

                  If any Apollo Stockholder elects to exercise its Bring-Along
Right, then it shall so notify the other Stockholders ("BRING-ALONG NOTICE") at
least ten (10) Business Days prior to the date on which such Apollo Stockholder
expects to consummate the Transfer giving rise to such Bring-Along Right. Each
Bring-Along Notice shall set forth: (i) the name of the Third Party Purchaser
and the number of shares of Common Stock proposed to be purchased by such Third
Party Purchaser, (ii) the proposed amount and form of consideration and terms
and conditions of payment offered by the Third Party Purchaser and a summary of
any other material terms pertaining to the Transfer ("THIRD PARTY TERMS") and
(iii) the number of shares of Common Stock that such Stockholder is required to
sell in such Transfer. The terms and conditions applicable to such purchase and
sale of any shares of Common Stock purchased from any Stockholder pursuant to
this SECTION 2 shall otherwise be the same as the terms and conditions
applicable to the Apollo Stockholder exercising the Bring-Along Right.

                  Upon the giving of a Bring-Along Notice, each Stockholder
shall be obligated to Transfer the number of shares of Common Stock required to
be Transferred by such Stockholder as set forth in the Bring-Along Notice on the
Third Party Terms.


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SECTION 3 TAG-ALONG RIGHTS

                  In the event that, at any time after the date hereof, one or
more of the Apollo Stockholders, in one transaction or a series of related
transactions proposes to Transfer twenty percent (20%) or more of the Common
Stock then held by such Apollo Stockholder to any Third Party Purchasers (other
than Apollo Affiliates), then each other Stockholder (collectively, the
"TAG-ALONG STOCKHOLDERS") shall have the right (the "TAG-ALONG RIGHT") to
Transfer the same percentage of his, her or its Common Stock as all Apollo
Stockholders are proposing to Transfer in such a transaction by requesting that
such Third Party Purchaser purchase from such Tag-Along Stockholder up to the
number of shares of Common Stock equal to the number derived by multiplying (i)
the total number of shares of Common Stock that the proposed Third Party
Purchaser(s) have agreed or committed to purchase by (ii) a fraction, the
numerator of which is the total number of shares of Common Stock owned by such
Tag-Along Stockholder, and the denominator of which is the total number of
shares of Common Stock then outstanding. If any IMC Stockholder is entitled to
transfer shares of Common Stock pursuant to this SECTION 3, references to
"Common Stock" shall mean "IMC Registered Stock" with respect to such IMC
Stockholder.

                  In the event any Apollo Stockholder proposes to make a
Transfer giving rise to the Tag-Along Right, such Apollo Stockholder shall
notify the other Stockholders (the "SALE NOTICE") at least ten (10) Business
Days prior to the date on which such Apollo Stockholder expects to consummate
such Transfer. Each Sale Notice shall set forth the Third Party Terms applicable
to the proposed Transfer. The terms and conditions applicable to such purchase
and sale of any shares of Common Stock purchased from the Tag-Along Stockholders
pursuant to this SECTION 3 shall otherwise be the same as the terms and
conditions applicable to the Apollo Stockholder proposing to make the Transfer
giving rise to the Tag-Along Right.

                  The Tag-Along Right may be exercised by any Tag-Along
Stockholder by delivery of a written notice to such Apollo Stockholder proposing
to Transfer shares of Common Stock (the "TAG-ALONG NOTICE") within five (5)
Business Days following receipt of a Sale Notice from such Apollo Stockholder.
The Tag-Along Notice shall state the number of shares of Common Stock (not to
exceed the amount determined in accordance with the first paragraph of this
SECTION 3) that such Tag-Along Stockholder proposes to include in such Transfer
to the Third Party Purchaser. In the event that the Third Party Purchaser does
not purchase the specified number of shares of Common Stock from the Tag-Along
Stockholders on the same terms and conditions as specified in the Sale Notice,
then such Apollo Stockholder shall not be entitled under this SECTION 3 to
Transfer any shares of Common Stock to the proposed Third Party Purchaser in the
proposed Transfer.

SECTION 4 REGISTRATION RIGHTS

        4.1 DEMAND REGISTRATION. At any time and from time to time after the IPO
Date, if the Company shall receive a written request from one or more Apollo
Investors (a "REQUESTING STOCKHOLDER"), that the Company file a registration
statement under the Securities Act (including a "shelf" registration statement
on Form S-3 or any successor form pursuant to Rule 415) covering the
registration of Registrable Common Stock pursuant to this SECTION 4.1 (a "DEMAND
NOTICE"), then the Company shall, within ten (10) business days of the receipt
of such written


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request, give written notice of such request ("REQUEST NOTICE") to all
Stockholders and, in addition to any obligations under SECTION 6, use its best
efforts to effect, as soon as practicable, the registration under the Securities
Act of all Registrable Common Stock that the Requesting Stockholder requests to
be registered in the Demand Notice together with the Registrable Common Stock of
other Registering Stockholders pursuant to SECTION 5, subject only to the
limitations of this SECTION 4 and the rights of other Stockholders pursuant to
SECTION 5; PROVIDED that the Company shall not be obligated to effect any such
registration until 180 days after the IPO Date.

        4.2 UNDERWRITING. If the Requesting Stockholder intends to distribute
the Registrable Common Stock covered by its request by means of an underwritten
offering, then it shall so advise the Company as a part of the Demand Notice,
and the Company shall include such information in the Request Notice. In such
event, the right of any Stockholder to include his Registrable Common Stock in
such registration shall be conditioned upon such Stockholder's participation in
such underwriting and the inclusion of such Stockholder's Registrable Common
Stock in the underwriting (unless otherwise mutually agreed by the Requesting
Stockholder and such Stockholder) as provided herein. The Company and all
Stockholders proposing to distribute their securities through such underwriting
shall enter into an underwriting agreement in customary form with the managing
underwriter or underwriters selected for such underwriting by the Requesting
Stockholder. Notwithstanding any other provision of this SECTION 4.2 or SECTION
5, if the managing underwriter(s) determine(s) in good faith that marketing
factors require a limitation of the number of securities to be underwritten,
then the Company shall so advise all Stockholders that would otherwise be
registered and underwritten pursuant hereto, and the managing underwriter(s) may
exclude shares of the Registrable Common Stock from the registration and the
underwriting, and the number of shares that will be included in the registration
and the underwriting shall be allocated, FIRST to the Requesting Stockholder's
Common Stock and to each of the Stockholders requesting inclusion of their
Registrable Common Stock in such registration statement pursuant to SECTION 5 on
a pro rata basis based on the total number of Registrable Common Stock requested
for inclusion in the registration by the Requesting Stockholder and each such
Stockholder, and SECOND to the Company. No other shares may be included (other
than by the Company or by the Stockholders pursuant to SECTION 5) without the
Requesting Stockholder's consent.

        4.3 DEFERRAL. Notwithstanding the foregoing, if the Company shall
furnish to the Requesting Stockholder a certificate signed by the President or
Chief Executive Officer of the Company stating that, in the good faith judgment
of the Board, it would be materially detrimental to the Company and its
stockholders for such registration statement then to be filed, the Company shall
have the right to defer such filings and, by notice to the Requesting
Stock-holder, to require the Requesting Stockholder to withdraw its Demand
Notice and to refrain from delivering another Demand Notice for a period of not
more than ninety (90) days after receipt of the request of the initial Demand
Notice; PROVIDED, HOWEVER, that the Company may not utilize this right more than
twice in any twelve (12) month period.

        4.4 IMC TRANSACTION STOCK. For purposes of this SECTION 4 and SECTIONS 5
AND 6, if the referred to Stockholder is an IMC Stockholder, references to
"Common Stock" shall mean "IMC Registered Stock" with respect to such IMC
Stockholder.


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SECTION 5 PIGGYBACK REGISTRATION RIGHTS

        5.1 If the Company at any time proposes to register under the Securities
Act any Common Stock or any security convertible into or exchangeable or
exercisable for Common Stock, whether or not for sale for its own account, on a
form and in a manner which would permit registration of the Common Stock held by
a Stockholder for sale to the public under the Securities Act (other than
pursuant to Form S-4 or Form S-8 or successor or similar forms), the Company
shall give written notice of the proposed registration to each Stockholder not
later than thirty (30) days prior to the filing thereof. Each Stockholder shall
have the right to request that all or any part of his or its Registrable Common
Stock be included in such registration. Any such registration that the Company
proposes for its own account shall be referred to as a "PRIMARY REGISTRATION"
and any such registration that the Company proposes that is not for its own
account shall be referred to as a "SECONDARY REGISTRATION." Each Stockholder can
make such a request by giving written notice to the Company within ten (10)
Business Days after the giving of such notice by the Company (any Stockholder
giving the Company a notice requesting that the Registrable Common Stock owned
by it be included in such proposed registration being hereinafter referred to in
this SECTION 5 as a "REGISTERING STOCKHOLDER"); PROVIDED, HOWEVER, that if the
Company or the managing underwriters of such offering determine that the
aggregate amount of securities of the Company which the Company, all Registering
Stockholders and all other Stockholders of the Company entitled to register
securities in connection with any offering ("OTHER REGISTERING HOLDERS") propose
to include in such registration statement exceeds the maximum amount of
securities that may be sold without having a material adverse effect on the
success of the offering, including without limitation the selling price and
other terms of such offering, the Company will include in such registration,
first, the securities which the Company proposes to sell in a Primary
Registration, second, the Registrable Common Stock of such Registering
Stockholders who are Apollo Stockholders, and third, the Registrable Common
Stock to be sold for the account of Other Registering Holders (including the IMC
Stockholders) and shares to be registered for the account of the Company in a
Secondary Registration, pro rata among all such Registering Stockholders and
such Other Registering Holders, taken together, on the basis of the relative
percentage of Registrable Common Stock owned by all such Registering
Stockholders and such Other Registering Holders who have requested that
securities owned by them be so included. Registrable Common Stock proposed to be
registered and sold pursuant to an underwritten offering for the account of any
Registering Stockholder shall be sold to the prospective underwriters selected
or approved by the Company and on the terms and subject to the conditions of one
or more underwriting agreements negotiated between the Company and the
prospective underwriters. Any Registering Stockholder who holds Registrable
Common Stock being registered in any offering shall have the right to receive a
copy of the form of underwriting agreement and shall have an opportunity to hold
discussions with the lead underwriter of the terms of such underwriting
agreement. The Company may withdraw any registration statement at any time
before it becomes effective, or postpone or terminate the offering of
securities, without obligation or liability to any Registering Stockholder.

SECTION 6 REGISTRATION PROCEDURES

        6.1 HOLDBACK AGREEMENTS. Notwithstanding any other provision of SECTION
4 or SECTION 5, each Stockholder agrees that (if so required by the underwriters
in an underwritten offering) he, she or it will not (and it shall be a condition
to the rights of each Stockholder under


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of SECTION 4 and SECTION 5 that such Stockholder does not) offer for public sale
any Common Stock during a period not to exceed sixty (60) days prior to and
one-hundred and eighty (180) days after the effective date of any registration
statement filed by the Company in connection with an underwritten public
offering (except as part of such underwritten registration or as otherwise
permitted by such underwriters). The IMC Stockholders shall not be required to
agree to any such holdback period that is longer than the shortest period
applicable to any Apollo Investor so long as the Apollo Investors beneficially
own at least as much as or more than the outstanding Common Stock beneficially
owned by the IMC Stockholders.

        6.2 EXPENSES. Except as otherwise required by state securities or blue
sky laws or the rules and regulations promulgated thereunder, all expenses,
disbursements and fees incurred by the Company and the Stockholders in
connection with any registration under SECTION 4 or under SECTION 5 shall be
borne by the Company, except that the following expenses shall be borne by the
Stockholder incurring the same: (i) the costs and expenses of counsel to such
Stockholder to the extent such Stockholder retains counsel; (ii) discounts,
commissions, fees or similar compensation owing to underwriters, selling
brokers, dealer managers or other industry professionals, to the extent relating
to the distribution or sale of such Stockholder's securities; (iii) transfer
taxes with respect to the securities sold by such Stockholder; and (iv) other
expenses incurred by such Stockholder and incidental to the sale and delivery of
the securities to be sold by such Stockholder.

        6.3 REGISTRATION PROCEDURES. In connection with any registration of
Registrable Common Stock under the Securities Act pursuant to this Agreement,
the Company will consult with each Registering Stockholder whose Common Stock is
to be included in any such registration concerning the form of underwriting
agreement, shall provide to such Registering Stockholder the form of
underwriting agreement prior to the Company's execution thereof and shall
provide to such Registering Stockholder and its representatives such other
documents (including comments by the Securities and Exchange Commission (the
"COMMISSION") on the registration statement) as such Registering Stockholder
shall reasonably request in connection with its participation in such
registration. The Company will furnish each Registering Stockholder whose shares
of Registrable Common Stock are registered thereunder and each underwriter, if
any, with a copy of the registration statement and all amendments thereto and
will supply each such Registering Stockholder and each underwriter, if any, with
copies of any prospectus included therein (including a preliminary prospectus
and all amendments and supplements thereto), in such quantities as may be
reasonably necessary for the purposes of the proposed sale or distribution
covered by such registration. In the event that the Company prepares and files
with the Commission a registration statement on any appropriate form under the
Securities Act (a "REGISTRATION STATEMENT") providing for the sale of
Registrable Common Stock held by any Registering Stockholder pursuant to its
obligations under SECTION 4 or SECTION 5, the Company will:

                (a) upon filing a Registration Statement or any prospectus
        related thereto (a "PROSPECTUS") or any amendments or supplements
        thereto, furnish to the Registering Stockholders whose Registrable
        Common Stock are covered by such Registration Statement and the
        underwriters, if any, copies of all such documents;


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                (b) prepare and file with the Commission such amendments and
        post-effective amendments to the Registration Statement as may be
        necessary to keep such Registration Statement effective for the ninety
        (90) day period referenced in paragraph (a) above; cause the related
        Prospectus to be supplemented by any required Prospectus supplement, and
        as so supplemented to be filed pursuant to Rule 424 under the Securities
        Act; and comply with the provisions of the Securities Act with respect
        to the disposition of all securities covered by such Registration
        Statement during the applicable period in accordance with the intended
        methods of disposition by the sellers thereof set forth in such
        Registration Statement or supplement to such Prospectus;

                (c) promptly notify the Registering Stockholders and the
        managing underwriters, if any, and (if requested by any such Person)
        confirm such advice in writing, (i) when a Prospectus or any Prospectus
        supplement or post-effective amendment has been filed, and, with respect
        to a Registration Statement or any post-effective amendment, when the
        same has become effective, (ii) of any request by the Commission or any
        state securities commission for amendments or supplements to a
        Registration Statement or related Prospectus or for additional
        information, (iii) of the issuance by the Commission or any state
        securities commission of any stop order suspending the effectiveness of
        a Registration Statement or the initiation of any proceedings for that
        purpose, (iv) of the receipt by the Company of any notification with
        respect to the suspension of the qualification of any of the Registrable
        Common Stock for sale in any jurisdiction or the initiation or
        threatening of any proceeding for such purpose, and (v) of the existence
        of any fact which results in a Registration Statement, a Prospectus or
        any document incorporated therein by reference containing an untrue
        statement of a material fact or omitting to state a material fact
        required to be stated therein or necessary to make the statements
        therein not misleading;

                (d) use its reasonable best efforts to obtain the withdrawal of
        any order suspending the effectiveness of a Registration Statement;

                (e) if requested by the managing underwriters or a Registering
        Stockholder, promptly incorporate in a Prospectus supplement or
        post-effective amendment such information as the managing underwriters
        or the Registering Stockholders holding a majority of the Registrable
        Common Stock being sold by Registering Stockholders agree should be
        included therein relating to the sale of such Registrable Common Stock,
        including without limitation information with respect to the amount of
        Registrable Common Stock being sold to such underwriters, the purchase
        price being paid therefor by such underwriters and with respect to any
        other terms of the underwritten (or best efforts underwritten) offering
        of the Registrable Common Stock to be sold in such offering; and make
        all required filings of such Prospectus supplement or post-effective
        amendment as soon as notified of the matters to be incorporated in such
        Prospectus supplement or post-effective amendment;

                (f) furnish to such Registering Stockholder and each managing
        underwriter at least one signed copy of the Registration Statement and
        any post-effective amendment thereto, including financial statements and
        schedules, all documents incorporated therein by reference and all
        exhibits (including those incorporated by reference);


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                (g) deliver to such Registering Stockholders and the
        underwriters, if any, as many copies of the Prospectus (including each
        preliminary prospectus) and any amendment or supplement thereto as such
        persons or entities may reasonably request;

                (h) prior to any public offering of Registrable Common Stock,
        register or qualify or cooperate with the Registering Stockholders, the
        underwriters, if any, and their respective counsel in connection with
        the registration or qualification of such Registrable Common Stock for
        offer and sale under the securities or blue sky laws of such
        jurisdictions within the United States as any Registering Stockholder or
        underwriter reasonably requests in writing and do any and all other acts
        or things necessary or advisable to enable the disposition in such
        jurisdictions of the Registrable Common Stock covered by the applicable
        Registration Statement; PROVIDED, HOWEVER, that the Company will not be
        required to qualify generally to do business in any jurisdiction where
        it is not then so qualified or to take any action which would subject it
        to general service of process or taxation in any such jurisdiction where
        it is not then so subject;

                (i) cooperate with the Registering Stockholders and the managing
        underwriters, if any, to facilitate the timely preparation and delivery
        of certificates representing Registrable Common Stock to be sold
        pursuant to such Registration Statement and not bearing any restrictive
        legends, and enable such Registrable Common Stock to be in such
        denominations and registered in such names as the managing underwriters
        may request at least two Business Days prior to any sale of Registrable
        Common Stock to the underwriters;

                (j) if any fact described in paragraph (c)(v) above exists,
        prepare a supplement or post-effective amendment to the applicable
        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
        Common Stock being sold thereunder, such Prospectus will not contain an
        untrue statement of a material fact or omit to state any material fact
        necessary to make the statements therein not misleading;

                (k) cause all Registrable Common Stock covered by the
        Registration Statement to be listed on each securities exchange on which
        similar securities issued by the Company are then listed;

                (l) provide a CUSIP number for all Registrable Common Stock
        included in such Registration Statement, not later than the effective
        date of the applicable Registration Statement;

                (m) make available for inspection by a representative of the
        Registering Stockholders the Registrable Common Stock being sold
        pursuant to such Registration Statement, any underwriter participating
        in any disposition pursuant to a Registration Statement, and any
        attorney or accountant retained by such Registering Stockholders or
        underwriter, all financial and other records, any pertinent corporate
        documents and properties of the Company reasonably requested by such
        representative, underwriter, attorney or accountant in connection with
        such Registration Statement; PROVIDED,


                                       11
<Page>

        HOWEVER, that any records, information or documents that are designated
        by the Company in writing as confidential shall be kept confidential by
        such persons or entities unless disclosure of such records, information
        or documents is required by court or administrative order;

                (n) otherwise use his, her or its reasonable best efforts to
        comply with all applicable rules and regulations of the Commission and
        relevant state securities commissions, and make generally available to
        the Registering Stockholders earning statements satisfying the
        provisions of SECTION 10(A) of the Securities Act no later than
        forty-five (45) days after the end of any 12-month period (or ninety
        (90) days, if such period is a fiscal year) commencing at the end of any
        fiscal quarter in which Registrable Common Stock of such Registering
        Stockholder is sold to underwriters in an underwritten offering, or, if
        not sold to underwriters in such an offering, beginning with the first
        month of the Company's first fiscal quarter commencing after the
        effective date of a Registration Statement, which statements shall cover
        said 12-month periods;

                (o) furnish to each underwriter, if an underwritten offering,
        customary "comfort" letters from its independent auditors, legal
        opinions from counsel to the Company on customary matters, and such
        other certificates, instruments or other matters reasonably requested by
        the underwriters;

                (p) cause the Company's executive officers, including its chief
        executive officer and chief financial officer, to be available to meet
        with potential investors and to participate in any "roadshow" requested
        by the underwriters and which in the underwriters' judgment is
        reasonably necessary or appropriate for the sale of the Registrable
        Common Stock; and

                (q) enter into such agreements (including an underwriting
        agreement in form reasonably satisfactory to the Company) and take all
        such other reasonable actions in connection with the sale of Registrable
        Common Stock.

        6.4 CONDITIONS TO STOCKHOLDER RIGHTS; INDEMNIFICATION BY STOCKHOLDER. It
shall be a condition of each Registering Stockholder's rights hereunder to have
Registrable Common Stock owned by it registered that:

                (a) such Registering Stockholder shall cooperate with the
        Company in all reasonable respects by supplying information and
        executing documents relating to such Registering Stockholder or the
        securities of the Company owned by such Registering Stockholder in
        connection with such registration;

                (b) such Registering Stockholder shall enter into such
        undertakings and take such other action relating to the conduct of the
        proposed offering which the Company or the underwriters may reasonably
        request as being necessary to ensure compliance with federal and state
        securities laws and the rules or other requirements of the NASD or
        otherwise to effectuate the offering; and


                                       12
<Page>

                (c) such Registering Stockholder shall execute and deliver an
        agreement to indemnify and hold harmless the Company and each
        underwriter (as defined in the Securities Act), and each person or
        entity, if any, who controls such underwriter within the meaning of the
        Securities Act, against such losses, claims, damages or liabilities
        (including reimbursement for legal and other expenses) to which such
        underwriter or controlling person or entity may become subject under the
        Securities Act or otherwise, in such manner as is customary for
        registrations of the type then proposed and, in any event, at least
        equivalent in scope to indemnities given by the Company in connection
        with such registration, but only with respect to information furnished
        by such Registering Stockholder specifically for use in the Registration
        Statement or Prospectus in connection with such registration and with
        respect to such Registering Stockholder's failure to deliver
        Prospectuses as required under the Securities Act; but such
        indemnification shall not extend to any amounts beyond the proceeds of
        the sale of the Securities received by such indemnitor.

        6.5 INDEMNIFICATION BY COMPANY. In the event of any registration under
the Securities Act of any Registrable Common Stock of Registering Stockholders
pursuant to this SECTION 6.5, the Company shall execute and deliver an agreement
to indemnify and hold harmless each Registering Stockholder and any underwriter
disposing of such Registrable Common Stock and any underwriter in connection
with such disposition against such losses, claims, damages or liabilities
(including reimbursement for legal and other expenses) to which such Registering
Stockholder may become subject under the Securities Act or otherwise, in such
manner as is customary in underwriting agreements for registrations of the type
then proposed.

SECTION 7 TRANSACTIONS WITH AFFILIATES AND OTHERS

                Prior to a Qualified Public Offering, so long as the IMC
Stockholders remain Stockholders of the Company, without the prior written
consent of IMC Global, the Company shall not enter into any transaction with any
Apollo Stockholder unless such transaction is on arms' length terms; PROVIDED,
HOWEVER, that the following shall be deemed to be on arms' length terms: (A) any
transaction authorized, based in part on a determination that such transaction
is fair as to the Company as of the time of authorization, by a majority of the
members of the Board of Directors who do not have a financial interest in such
transaction within the meaning of the General Corporation Law of the State of
Delaware, (B) any amendment or modification to the terms of the Preferred Stock
or the Note Securities that treats all outstanding shares of Preferred Stock or
all outstanding Note Securities similarly, (C) any agreements to be entered into
by the Company regarding tax reporting on IRS Form 1099-DIV (or any successor
form) with respect to the Series A Preferred Stock, (D) the Management
Consulting Agreement and the transactions and payments thereunder, and (E) any
reasonable and customary fees, stock options, reasonable out-of-pocket expense
reimbursements, coverage under directors and officers insurance and
indemnification protection for officers and directors received by or covering
any Apollo Stockholder.


                                       13
<Page>

SECTION 8 ADDITIONAL COMPANY EQUITY ISSUANCES TO APOLLO STOCKHOLDERS.

                Prior to a Qualified Public Offering, the Company shall not
issue any Securities to any Apollo Stockholder unless the Company shall offer to
each of the IMC Stockholders an opportunity to acquire the Securities, in an
amount up to the Pre-Emptive Percentage of the total amount of such Securities
to be issued, on the same terms and conditions as the Apollo Stockholders,
provided that such opportunity must be offered to the IMC Stockholders no later
than 30 days after the acquisition of any such Securities by any Apollo
Stockholder and any IMC Stockholder must determine whether to participate within
ten days of such offer (which determination may be conditioned upon the
participation of any of the Apollo Stockholders); PROVIDED HOWEVER, during the
period beginning on the date that the Apollo Stockholders acquire such
Securities and ending on the earliest of the dates on which (A) the IMC
Stockholders' right to participate lapses, (B) the IMC Stockholders purchase
Securities following an election to participate, or (C) the IMC Stockholders
notify the Company that they will not participate, the Company shall not (x) set
a record date for payment of dividends, (y) seek stockholder approval for any
matter (unless, taking into account the total amount of Securities that the IMC
Stockholders are entitled to purchase if the IMC Stockholders elect to
participate, the vote of the IMC Stockholders would not alter the outcome of the
sought after approval and the act of voting or refraining from voting would not
give rise to specific rights, including dissenters rights) or (z) enter into or
effect, or agree to enter into or effect, a merger, consolidation, sale
recapitalization, or similar transaction, unless, in any case contemplated by
clauses (x), (y) and (z), the IMC Stockholders receive the same benefits and
rights and are subject to the same obligations as if the IMC Stockholders had
purchased the Securities on the same date as the Apollo Stockholders.

SECTION 9 MISCELLANEOUS

        9.1 TERMINATION. Notwithstanding any other provision contained herein,
the rights and obligations of all Parties under SECTIONS 2, and 3 shall
terminate upon the date on which a Qualified Public Offering is consummated.

        9.2 LEGENDS. Each certificate representing shares of Common Stock held
by the Stockholders shall bear the following legend:

                  "THE SECURITIES REPRESENTED BY THIS CERTIFICATE HAVE NOT BEEN
                  REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE
                  "ACT"), OR THE SECURITIES LAWS OF ANY STATE AND MAY NOT BE
                  SOLD OR TRANSFERRED IN THE ABSENCE OF AN EFFECTIVE
                  REGISTRATION STATEMENT UNDER THE ACT AND SUCH LAWS OR AN
                  EXEMPTION FROM THE REGISTRATION REQUIREMENTS THEREOF."

                  "THE SECURITIES REPRESENTED HEREBY ARE SUBJECT TO ADDITIONAL
                  RESTRICTIONS ON TRANSFER AND CERTAIN OTHER AGREEMENTS SET
                  FORTH IN A STOCK RIGHTS AGREEMENT BETWEEN THE ISSUER AND THE
                  INITIAL HOLDER HEREOF DATED AS OF NOVEMBER 28, 2001. A COPY OF
                  SUCH


                                       14
<Page>

                  AGREEMENT SHALL BE FURNISHED WITHOUT CHARGE BY THE ISSUER
                  TO THE HOLDER HEREOF UPON WRITTEN REQUEST."

        9.3 SUCCESSORS, ASSIGNS AND TRANSFEREES. This Agreement shall be binding
upon and inure to the benefit of the Parties hereto and their respective legal
representatives, heirs, legatees, successors, and assigns and any other
transferee of the Common Stock, Preferred Stock or IMC Notes and shall also
apply to any Common Stock, Preferred Stock or IMC Notes acquired by Stockholders
after the date hereof.

        9.4 SPECIFIC PERFORMANCE. Each Party, in addition to being entitled to
exercise all rights provided herein or granted by law, including recovery of
damages, shall be entitled to specific performance of each other Party's
obligations under this Agreement. The Parties agree that monetary damages would
not be adequate compensation for any loss incurred by reason of a breach by any
of them of the provisions of this Agreement and each hereby agrees to waive the
defense in any action for specific performance that a remedy at law would be
adequate.

        9.5 GOVERNING LAW. This Agreement shall be governed by and construed in
accordance with the internal laws, and not the law of conflicts, of the State of
New York.

        9.6 SUBMISSION TO JURISDICTION; WAIVER OF JURY TRIAL. EACH PARTY HERETO
HEREBY SUBMITS TO THE NONEXCLUSIVE JURISDICTION OF THE UNITED STATES DISTRICT
COURT FOR THE SOUTHERN DISTRICT OF NEW YORK AND OF ANY NEW YORK STATE COURT
SITTING IN NEW YORK CITY FOR PURPOSES OF ALL LEGAL PROCEEDINGS ARISING OUT OF OR
RELATING TO THIS STOCK RIGHTS AGREEMENT OR THE TRANSACTIONS CONTEMPLATED HEREBY.
EACH PARTY HERETO IRREVOCABLY WAIVES, TO THE FULLEST EXTENT PERMITTED BY LAW,
ANY OBJECTION WHICH IT MAY NOW OR HEREAFTER HAVE TO THE LAYING OF THE VENUE OF
ANY SUCH PROCEEDING BROUGHT IN SUCH A COURT AND ANY CLAIM THAT ANY SUCH
PROCEEDING BROUGHT IN SUCH A COURT HAS BEEN BROUGHT IN AN INCONVENIENT FORUM.
EACH PARTY HERETO IRREVOCABLY WAIVES ANY AND ALL RIGHT TO TRIAL BY JURY IN ANY
LEGAL PROCEEDING ARISING OUT OF OR RELATING TO THIS STOCK RIGHTS AGREEMENT OR
THE TRANSACTIONS CONTEMPLATED HEREBY.

        9.7 INTERPRETATION. The headings of the Sections contained in this
Agreement are solely for the purpose of reference, are not part of the agreement
of the Parties and shall not affect the meaning or interpretation of this
Agreement.

        9.8 REPRESENTATION. Apollo Management shall represent each of the Apollo
Stockholders for the purposes of this Agreement, including with respect to any
waivers, consent or notices and it has the requisite authority to represent each
of the entities comprising the Apollo Stockholders. Any notice given by Apollo
Management shall be deemed to also have been given by the Apollo Investors or
the Apollo Stockholders, as the case may be, and shall be binding on all of the
Apollo Investors and Apollo Stockholders. IMC Global shall represent each of the
IMC Stockholders for the purposes of this Agreement, including with respect to
any waivers,


                                       15
<Page>

consent or notices and it has the requisite authority to represent each of the
entities comprising the IMC Stockholders.

        9.9 NOTICES. All notices and other communications provided for or
permitted hereunder shall be in writing and shall be deemed to have been duly
given and received when delivered by overnight courier or hand delivery, when
sent by telecopy, or five days after mailing if sent by registered or certified
mail (return receipt requested) postage prepaid, to the Parties at the following
addresses (or at such other address for any Party as shall be specified by like
notices, provided that notices of a change of address shall be effective only
upon receipt thereof).

                  If to the Company, at:

                           Salt Holdings Corporation
                           8300 College Park Boulevard
                           Overland Park, Kansas 66210
                           Attention:   Chief Executive Officer


                           With a copy to Apollo, at the address given below,
and a copy to:

                           Latham & Watkins LLP
                           885 Third Avenue
                           New York, N.Y. 10022
                           Attention:  Raymond Y. Lin
                           Facsimile: (212) 751-4864

                  If to Apollo, at:

                           Apollo Management, L.P.
                           1301 Avenue of the Americas
                           New York, NY 10019
                           Attention:   Scott Kleinman
                           Facsimile:   212-515-3232

                           With a copy to Latham & Watkins LLP, at the address
given above.

                  If to IMC Global Inc., to:

                           IMC Global Inc.
                           100 South Saunders Road, Suite 300
                           Lake Forest, IL  60045
                           Attention:   General Counsel
                           Facsimile:   (847) 739-1606



                                       16
<Page>

                           with a copy to:

                           Skadden Arps Slate Meagher & Flom LLP
                           4 Times Square
                           New York, N.Y. 10036
                           Attention:       Stephen Arcano
                           Facsimile:       (212) 735-2000

                  If to any other Stockholder, to the address set forth on the
signature pages hereto.

        9.10 RECAPITALIZATION, EXCHANGE, ETC. AFFECTING THE COMPANY'S EQUITY
SECURITIES. The provisions of this Agreement shall apply, to the full extent set
forth herein, with respect to any and all Securities or any successor or assign
of the Company (whether by merger, consolidation, sale of assets, conversion to
a corporation or otherwise) that may be issued in respect of, in exchange for,
or in substitution of, the Securities and shall be appropriately adjusted for
any dividends, splits, reverse splits, combinations, recapitalizations, and the
like occurring after the date hereof.

        9.11 COUNTERPARTS. This Agreement may be executed in two or more
counterparts, each of which shall be deemed to be an original and all of which
together shall be deemed to constitute one and the same agreement.

        9.12 SEVERABILITY. In the event that any one or more of the provisions
contained herein, or the application thereof in any circumstances, is held
invalid, illegal, or unenforceable in any respect for any reason, the validity,
legality and enforceability of any such provision in every other respect and of
the remaining provisions contained herein shall not be in any way impaired
thereby.

        9.13 AMENDMENT. This Agreement may be amended only by written agreement
signed by each of the parties hereto. Notwithstanding the foregoing, at any time
hereafter, any Persons acquiring shares of Common Stock in accordance with the
terms hereof may be made parties hereto by executing a signature page in the
form attached as EXHIBIT A hereto, which signature page shall be countersigned
by the Company and shall be attached to this Agreement and become a part hereof
without any further action of any other Party hereto.



                                       17
<Page>


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

                          SALT HOLDINGS CORPORATION


                          By:
                                   --------------------------------------------
                                   Name:
                                   Title:


                          APOLLO MANAGEMENT V L.P.


                          By:
                                   --------------------------------------------
                                   Name:
                                   Title:


                          YBR HOLDINGS LLC


                          By:
                                   --------------------------------------------
                                   Name:
                                   Title:


                          YBR NETHERLANDS I, L.P.


                          By:
                                   --------------------------------------------
                                   Name:
                                   Title:


                          YBR NETHERLANDS II, L.P.


                          By:
                                   --------------------------------------------
                                   Name:
                                   Title:


                          IMC GLOBAL INC.


                          By:
                                   --------------------------------------------
                                   Name:
                                   Title:




<Page>


                                   SCHEDULE A

                                  STOCKHOLDERS

YBR Holdings LLC
YBR Netherlands I, L.P.
YBR Netherlands II, L.P.



<Page>

                                    EXHIBIT A

                                 SIGNATURE PAGE
                                     TO THE
                              AMENDED AND RESTATED
                             STOCK RIGHTS AGREEMENT

                  By execution of this signature page, __________________
hereby agrees to become a party to, be bound by the obligations of and receive
the benefits of that certain Amended and Restated Stock Rights Agreement dated
as of June 23, 2003 by and among Salt Holdings Corporation, a Delaware
corporation, Apollo Management V L.P., a Delaware limited partnership, each of
the stockholders of the Company listed on Schedule A attached thereto, IMC
Global Inc., a Delaware corporation, and certain other parties named therein, as
amended from time to time thereafter.

                            ____________________________________________________


                            By:
                                     ___________________________________________
                                     Name:
                                     Title:


                            Notice Address:


                            ____________________________________________________

                            ____________________________________________________

                            ____________________________________________________


Accepted:


SALT HOLDINGS CORPORATION



By:
         ___________________________________________
         Name:
         Title: