<PAGE>   1


                                                                 EXHIBIT (4) (d)

                                 AMENDMENT NO. 3
                                       TO
                           LOAN AND SECURITY AGREEMENT

     THIS AMENDMENT NO. 3 dated as of December 17, 1999 (this "Amendment") is
entered into among BANK OF AMERICA, NATIONAL ASSOCIATION ("B of A"), as
successor to BankAmerica Business Credit, Inc., Bank of America, National Trust
and Savings Association and NationsBank, N.A., and GMAC COMMERCIAL CREDIT LLC, a
New York limited liability company ("GMAC"), as successor to BNY Financial
Corporation, formerly known as Bank of New York Commercial Corporation, (B of A
and GMAC and their respective successors and assigns being sometimes hereinafter
referred to collectively as the "Lenders" and each of B of A and GMAC and its
successors and assigns being sometimes hereinafter referred to individually as a
"Lender"), B of A (as successor to BankAmerica Business Credit, Inc. and Bank of
America, National Trust and Savings Association), as agent for the Lenders (in
such capacity as agent, the "Agent"), LACLEDE STEEL COMPANY, a Delaware
corporation, as debtor and debtor-in-possession (the "Parent"), LACLEDE CHAIN
MANUFACTURING COMPANY, a Delaware corporation, as debtor and
debtor-in-possession ("Laclede Chain"), and LACLEDE MID AMERICA INC., an Indiana
corporation, as debtor and debtor-in-possession ("Laclede Mid America") (the
Parent, Laclede Chain and Laclede Mid America being sometimes hereinafter
referred to collectively as the "Borrowers" and each of the Parent, Laclede
Chain and Laclede Mid America being sometimes hereinafter referred to
individually as a "Borrower").

                              W I T N E S S E T H:

     WHEREAS, the Borrowers, the Lenders and the Agent are parties to a certain
Loan and Security Agreement dated as of December 1, 1998, as amended by
Amendment No. 1 dated as of December 23, 1998 and Amendment No. 2 dated as of
July 1, 1999 (such Loan and Security Agreement, as so amended, the "Loan
Agreement," capitalized terms used herein without definition having the meanings
given such terms in the Loan Agreement, as amended by this Amendment); and

     WHEREAS, the Borrowers, the Lenders and the Agent have agreed to amend the
Loan Agreement on the terms and conditions hereinafter set forth;

     NOW, THEREFORE, in consideration of the premises set forth above, and for
other good and valuable consideration, the receipt and sufficiency of which are
hereby acknowledged, the Borrowers, the Lenders and the Agent hereby agree as
follows:

     Section 1. Amendment of the Loan Agreement. Subject to the fulfillment of
the conditions precedent set forth in Section 4 below, the Loan Agreement is
amended as follows:

     (a) Section 1.1 is amended by deleting the definitions of "Agreed
Pre-Petition Outstanding Balance" and "Inventory Sublimit Amount."

     (b) Section 1.1 is further amended by amending and restating the definition
of "Bank of America" as follows:

     "Bank of America" means Bank of America, National Association, a national
banking association, or any successor entity thereto.

     (c) Section 1.1 is further amended by amending and restating the definition
of "Base Rate Loan" as follows:




<PAGE>   2


          "Base Rate Loan" means a Post-Petition Revolving Loan or Post-Petition
     Term Loan during any period in which it bears interest at the rate provided
     in Section 3.1(i).

     (d) Section 1.1 is further amended by amending and restating the definition
of "LIBOR Loan" as follows:

          "LIBOR Loan" means a Post-Petition Revolving Loan or Post-Petition
     Term Loan during any period in which it bears interest at the rate provided
     in Section 3.1(ii).

     (e) Section 1.1 is further amended by amending and restating clause (a) of
the definition of "Maximum Revolver Amount" as follows:

     (a) the lesser of

          (i) the Revolver Facility minus the amount of Term Loans outstanding
          at such time and the amount of any Pre-Petition Obligations
          outstanding at such time; or

          (ii) (A) eighty-five percent (85.0%) of the Net Amount of the Eligible
          Accounts; plus (B) the lesser of (1) sixty-five percent (65.0%) of the
          value of Net Eligible Inventory; and (2) $38,500,000; provided, that
          the amount of Revolving Loans based upon Eligible Inventory consisting
          of supplies shall be limited to the Supplies Inventory Sublimit
          Amount; plus (C) the amount of the Additional Facility at such time
          minus (D) the amount of Pre-Petition Revolving Loans outstanding at
          such time;

     (f) Section 1.1 is further amended by adding the following definitions in
alphabetical order:

          "Post-Petition Term Loans" means Term Loans made pursuant to this
          Agreement.

          "Pre-Petition Term Loans" means Term Loans made pursuant to the
          Original Agreement.

          "Supplies Inventory Sublimit Amount" means the amount set forth below
     for the period indicated:

<TABLE>
<CAPTION>
          Period                                                 Amount
          ------                                                 ------
<S>                                                             <C>
          Effective date of Amendment
          No. 3 hereto through
          December 31, 1999                                      $ 6,000,000
          January 2000                                             6,000,000
          February 2000                                            5,750,000
          March 2000                                               5,500,000
          April 2000                                               5,250,000
          May 2000                                                 5,000,000
          June 2000                                                4,750,000
</TABLE>

In determining the Eligibility Inventory that is subject to the Supplies
Inventory Sublimit Amount, zinc and pipe couplings will be treated as raw
materials rather than supplies.

     (g) Section 1.1 is further amended by amending and restating the definition
of "Stated Termination Date" as follows:




<PAGE>   3


          "Stated Termination Date" means June 30, 2000.

          (h) Section 1.1 is further amended by amending and restating the
     definition of "Term Loans" as follows:

          "Term Loans" means, collectively, Pre-Petition Term Loans and
     Post-Petition Term Loans.

          (i) Section 3.1 is amended and restated as follows:

          3.1 Interest Rates. All outstanding Post-Petition Obligations shall
     bear interest on the unpaid principal amount thereof (including, to the
     extent permitted by law, on interest thereon not paid when due) from the
     date made until paid in full in cash at a rate determined by reference to
     the Base Rate or the LIBO Rate and Sections 3.1(i) or (ii), as applicable,
     but not to exceed the Maximum Rate described in Section 3.4. Subject to the
     provisions of Section 3.2, any of the Post-Petition Revolving Loans or
     Post-Petition Term Loans may be converted into, or continued as, Base Rate
     Loans or LIBOR Loans in the manner provided in Section 3.2. If at any time
     Post-Petition Revolving Loans or Post-Petition Term Loans are outstanding
     with respect to which notice has not been delivered to the Agent in
     accordance with the terms of this Agreement specifying the basis for
     determining the interest rate applicable thereto, then those Post-Petition
     Revolving Loans or Post-Petition Term Loans shall be Base Rate Loans and
     shall bear interest at a rate determined by reference to the Base Rate
     until notice to the contrary has been given to the Agent and such notice
     has become effective. Except as otherwise provided herein, the outstanding
     Post-Petition Obligations shall bear interest as follows:

          (i) For all Post-Petition Revolving Loans, Post-Petition Term Loans
     and other Post-Petition Obligations which are not LIBOR Loans, then at a
     fluctuating per annum rate to two percent (2.00%) plus the Base Rate;

          (ii) For all Post-Petition Revolving Loans and Post-Petition Term
     Loans which are LIBOR Loans, then at a per annum rate equal to four percent
     (4.00%) plus the LIBO Rate determined for the applicable Interest Period.

     Each change in the Base Rate shall be reflected in the interest rate
     described in (i) above as of the effective date of such change. All
     interest charges shall be computed on the basis of a year of 360 days and
     actual days elapsed. Except as otherwise provided herein, (a) interest
     accrued on each LIBOR Loan shall be payable in arrears on the first day of
     each month hereafter, and (b) interest accrued on the Base Rate Loans will
     be payable in arrears on the first day of each month hereafter.

          (j) Subsection (a) of Section 3.2 is amended and restated as follows:

          (a) Subject to the provisions of Section 3.3, (i) the Borrowers shall
     have the option to convert all or any part of the outstanding Post-Petition
     Revolving Loans or Post-Petition Term Loans, in a minimum amount of
     $5,000,000 and integral multiples of $5,000,000 in excess of that amount,
     from Base Rate Loans to LIBOR Loans at any time; (ii) the Borrowers shall
     have the option to convert all or any part of the outstanding Post-Petition
     Revolving Loans or Post-Petition Term Loans from LIBOR Loans to Base Rate
     Loans on the expiration of the Interest Period applicable thereto; and
     (iii) the Borrowers shall have the option, on the expiration of the
     Interest Period applicable to any outstanding LIBOR Loan, to continue all
     or any portion of such LIBOR Loan equal to $5,000,000 and integral
     multiples of $5,000,000 in excess of that amount, as a LIBOR Loan;
     provided, however, that no outstanding Loans may be converted into or
     continued as LIBOR Loans when any Default or Event of Default has occurred
     and is continuing. Any



<PAGE>   4


         conversion or continuation made with respect to less than the entire
         outstanding balance of the Post-Petition Revolving Loans or
         Post-Petition Term Loans must be applied pro rata to the Revolving
         Loans or Term Loans, as applicable, according to the outstanding
         principal balance of each Revolving Loan or each Term Loan.

               (k)  Section 4.2 is amended and restated as follows:

               4.2 Scheduled Payments and Mandatory Prepayments of the Term
         Loans. The Borrowers shall make monthly principal payments on the
         Post-Petition Term Loans in the aggregate amount of $70,000, due and
         payable on the first day of each calendar month, commencing on January
         1, 2000, until the earlier of (a) the Stated Termination Date, or (b)
         the payment in full of the Post-Petition Term Loans. In addition,
         prepayments on the Term Loans shall be required to be made as provided
         in Sections 5.11(c), 8.5(c), 8.6(b) and 8.9(b). In addition, after the
         Additional Facility has been reduced to zero, (1) if any amounts are
         received with respect to items (a), (b), or (f) on Exhibit D, then 50%
         of such amounts shall be applied to the prepayment of the Term Loans,
         applying such amounts ratably to the installments of the Term Loans in
         the inverse order of maturity, and (2) if any Net Proceeds of the
         Electrode Settlement are received such that the amount of all Net
         Proceeds of the Electrode Settlement at such time is in excess of
         $2,500,000, then 100% of such excess Net Proceeds shall be applied to
         the prepayment of the Term Loans, applying such amounts ratably to the
         installments of the Term Loans in the inverse order of maturity.

               (l) Section 4.5 is amended by amending and restating clause
          "second" as follows:

          second, from and after the entry of the Final Order, through and
          including December 31, 1999, to make Adequate Protection Payments;

               (m) Section 4.5 is further amended by amending and restating
          clause "fourth" as follows:

          fourth, until the outstanding Pre-Petition Obligations have been paid
          in full, to pay the principal of the Pre-Petition Revolving Loans;

               (n) The last sentence of Section 8.9(b) is amended and restated
          as follows:

          Upon any such sale or other disposition, the entire amount of Net
          Proceeds shall be applied on the date of such sale or disposition to
          the repayment of the Term Loans, and if the Term Loans have been
          repaid in full, to any other Post-Petition Obligations then
          outstanding.

               (o) Section 8.24 is amended and restated as follows:

               8.24 Cash Available for Fixed Charges. The Borrowers will
          maintain Cash Available for Fixed Charges, determined as of the end of
          each period listed below for the period indicated, of not less than
          the following:

<TABLE>
<CAPTION>
                                                           Cash Available for
                  Period                                     Fixed Charges
                  ------                                     -------------
<S>                                                           <C>
          Ten month period ending 9/30/99                     $  (100,000)
          Thirteen month period ending 12/31/99               $ 1,400,000
</TABLE>




<PAGE>   5


<TABLE>
<CAPTION>
                                                           Cash Available for
                   Period                                    Fixed Charges
                   ------                                    -------------
<S>                                                           <C>
          Sixteen month period ending 3/31/00                 $ 2,100,000
          Nineteen month period ending 6/30/00                $ 2,900,000
</TABLE>

          In determining Cash Available for Fixed Charges, non-cash pension
          expense other than service costs will not be deducted from net
          earnings.

               (p) Section 8.25 is amended and restated as follows:

               8.25 Direct Contribution. The Direct Contribution of the Alton
          Steel Operations will not be less than the following amounts for the
           following periods:

<TABLE>
<CAPTION>
                   Period                                        Amount
                   ------                                        ------
<S>                                                           <C>
          Nine months ending 9/30/99                          $ (1,500,000)
          Twelve months ending 12/31/99                       $ (1,700,000)
          Fifteen months ending 3/31/00                       $  1,000,000
          Eighteen months ending 6/30/00                      $  1,500,000
</TABLE>

          In determining Direct Contribution, non-cash pension expense other
          than service costs will not be deducted from net income.

               (q) Section 13.11 is amended to delete the wire transfer
          instructions for NB, and Section 14.7 is amended to delete the address
          provision for NB.

               Section 2. Bank of America Reorganization. As a result of the
          distribution of the assets of BankAmerica Business Credit, Inc. to
          Bank of America National Trust and Savings Association (the name of
          which was subsequently changed to Bank of America, National
          Association), and the merger of NationsBank, N.A. with and into Bank
          of America, National Association with the surviving entity in such
          merger being Bank of America, National Association, all references to
          BankAmerica Business Credit, Inc., BABC, Bank of America National
          Trust and Savings Association, Bank of America, NationsBank, N.A. and
          NB contained in the Loan Agreement shall hereafter be deemed to be
          references to Bank of America, National Association.

               Section 3. Pre-Petition Revolving Loans, Pre-Petition Term Loans
          and Adequate Protection Payments. The Agent, the Lenders and the
          Borrowers hereby agree that on the date upon which this Amendment
          shall become effective, the Borrowers shall borrow (a) Post-Petition
          Revolving Loans to repay in full the Pre-Petition Revolving Loans, and
          (b) Post-Petition Term Loans to repay in full the Pre-Petition Term
          Loans, so that as of such date, the balance of the Pre-Petition
          Obligations shall be zero, and the Borrowers hereby direct the Lenders
          to advance such Post-Petition Revolving Loans and Post-Petition Term
          Loans on such effective date. In addition, the Agent, the Lenders and
          the Borrowers agree that any Adequate Protection Payments received by
          the Agent or the Lenders pursuant to the Loan Agreement shall be
          applied first, to pay any interest due on the Pre-Petition
          Obligations, including interest accrued after the Petition Date at the
          rates set forth under the Loan Agreement and second, to reduce the
          principal amount due on the Term Loans. The Borrowers shall make the
          final Adequate Protection Payment on December 31, 1999, after which
          date the Borrowers shall not be required to make any further Adequate
          Protection Payments; provided, that the right of the Borrowers to
          cease making Adequate Protection Payments is without prejudice to, and
          does not constitute a waiver of, expressly or implicitly,



<PAGE>   6


the right of the Lenders hereafter to request additional adequate protection of
their interests in the Collateral or relief from or modification of the
automatic stay under Section 362 of the Bankruptcy Code. The Borrowers shall
make monthly principal payments on the Post-Petition Term Loans in the aggregate
amount of $70,000, due and payable on the first day of each calendar month,
commencing on January 1, 2000, until the earlier of (a) the Stated Termination
Date, or (b) the payment in full of the Post-Petition Term Loans.

     Section 4. Conditions to Amendment. This Amendment shall become effective
upon (a) the receipt by the Agent by facsimile transmission of a counterpart of
this Amendment executed by each Borrower and each Lender, and execution of this
Amendment by the Agent (provided, that each Borrower and each Lender shall
promptly execute six applicable signature pages hereof and deliver such pages to
the Agent), and (b) entry by the Bankruptcy Court of a final order acceptable to
the Agent approving the terms hereof, and such order being in full force and
effect and (unless waived by the Agent) not subject to reversal, stay,
modification, amendment or appeal.

     Section 5. Representations and Warranties. Each Borrower hereby represents
and warrants that (i) this Amendment constitutes a legal, valid and binding
obligation of such Borrower, enforceable against such Borrower in accordance
with its terms, (ii) the representations and warranties contained in the Loan
Agreement are correct in all material respects as though made on and as of the
date of this Amendment, and (iii) no Event of Default has occurred and is
continuing.

     Section 6. Reference to and Effect on the Loan Agreement.

     (a) Upon the effectiveness of this Amendment, each reference in the Loan
Agreement to "this Agreement", "hereunder", "hereof", "herein", or words of like
import shall mean and be a reference to the Loan Agreement, as amended hereby,
and each reference to the Loan Agreement in any other document, instrument or
agreement executed and/or delivered in connection with the Loan Agreement shall
mean and be a reference to the Loan Agreement, as amended hereby.

     (b) Except as specifically amended above, the Loan Agreement and all other
documents, instruments and agreements executed and/or delivered in connection
therewith shall remain in full force and effect and are hereby ratified and
confirmed.

     (c) The execution, delivery and effectiveness of this Amendment shall not
operate as a waiver of any right, power or remedy of the Agent or the Lenders
under the Loan Agreement, nor constitute a waiver of any provision of the Loan
Agreement, except as specifically set forth herein.

     Section 7. Execution in Counterparts. This Amendment may be executed in any
number of counterparts and by different parties hereto in separate counterparts,
each of which when so executed and delivered shall be deemed to be an original
and all of which taken together shall constitute but one and the same
instrument.

     Section 8. Governing Law. This Amendment shall be governed by and construed
in accordance with the internal laws (as opposed to the conflicts of laws
provisions) of the State of Illinois.

     Section 9. Section Titles. The section titles contained in this Amendment
are and shall be without substance, meaning or content of any kind whatsoever
and are not a part of the agreement between the parties hereto.




<PAGE>   7


     Section 10. Parties, Successors and Assigns. This Amendment shall be
binding upon and shall inure to the benefit of the Borrowers, the Agent, each
Lender, and their respective successors and assigns.

     Section 11. Severability. To the extent any provision of this Amendment is
not enforceable under applicable law, such provision shall be deemed null and
void and shall have no effect on the remaining portions of the Amendment.

     Section 12. Construction of Amendment. Each party hereto has cooperated in
the drafting and preparation of this Amendment and, as a result, this Amendment
shall not be construed against any party. This Amendment may be amended or
modified only by a written agreement signed by the parties hereto. This
Amendment may be executed in counterparts, each of which when so executed and
delivered shall be deemed an original but all such counterparts together shall
constitute one and the same instrument.




<PAGE>   8



     IN WITNESS WHEREOF, the parties hereto have caused this Amendment to be
duly executed and delivered as of December 17, 1999.


                                    LACLEDE STEEL COMPANY, as
                                    Debtor and Debtor-in-Possession


                                    By:_______________________________
                                       Vice President

                                    LACLEDE CHAIN MANUFACTURING COMPANY, as
                                    Debtor and Debtor-in-Possession


                                    By:________________________________
                                       Vice President

                                    LACLEDE MID AMERICA INC., as
                                    Debtor and Debtor-in-Possession





<PAGE>   9



                                    By:________________________________
                                       Vice President

                                    BANK OF AMERICA, NATIONAL ASSOCIATION,
                                    (as successor to BankAmerica Business
                                    Credit, Inc. and Bank of America National
                                    Trust and Savings Association), as the
                                    Agent


                                    By:________________________________
                                       Vice President

                                    BANK OF AMERICA, NATIONAL ASSOCIATION,
                                    (as successor to BankAmerica Business
                                    Credit, Inc., Bank of America National
                                    Trust and Savings Association and
                                    NationsBank, N.A.), as a Lender


                                    By:________________________________
                                       Vice President

                                    GMAC COMMERCIAL CREDIT LLC, (as successor
                                    to BNY Financial Corporation, formerly
                                    known as The Bank of New York Commercial
                                    Corporation), as a Lender


                                    By:________________________________
                                       Vice President