**EXECUTION
      VERSION**




SECOND AMENDMENT TO THE 5-YEAR CREDIT AGREEMENT




This
      amendment (the " Amendment "),
      dated
      as of October 26, 2006, is entered into by and among NORTHERN
      ILLINOIS GAS COMPANY and
      NICOR
      INC. (each, a " Borrower "
      and
      collectively, the " Borrowers "),
      JPMORGAN CHASE BANK, N.A., in its capacity as administrative agent (in such
      capacity, the " Administrative
      Agent "),
      and
      certain of the lenders constituting the Required Lenders (as defined in the
      5-Year Credit Agreement, defined below).




The
      Borrowers, the Administrative Agent and, among others, the financial
      institutions party thereto (the " Lenders "),
      are
      parties to the 5 year credit agreement dated as of September 13, 2005 (as
      modified and supplemented and in effect from time to time, the " 5-Year
      Credit Agreement "),
      providing, subject to the terms and conditions thereof, several commitments
      of
      the Lenders to make available a revolving letter of credit facility for loans
      to
      the Borrowers in an aggregate principal or face amount of
      $600,000,000.




The
      Borrowers, the Administrative Agent and the Lenders party to the 5-Year Credit
      Agreement constituting the Required Lenders, wish now to amend the 5-Year Credit
      Agreement in certain respects, and accordingly, the parties hereto hereby agree
      as follows:




Section
      1.  Definitions .
      Except
      as otherwise defined in this Amendment, terms defined in the 5-Year Credit
      Agreement are used herein (and in the introductions and recitals hereto) as
      defined therein.




Section
      2.  Amendments .
      Subject
      to the satisfaction of the conditions precedent specified in Section
      4 below,
      but effective as of the date hereof, the 5-Year Credit Agreement shall be
      amended as follows:




2.01. References
      Generally .
      References in the 5-Year Credit Agreement (including references to the 5-Year
      Credit Agreement as amended hereby) to "this Agreement" (and indirect references
      such as "hereunder," "hereby," "herein" and "hereof") shall be deemed to be
      references to the 5-Year Credit Agreement as amended hereby.




2.02. Definitions . Section
      1.1 of the
      5-Year Credit Agreement shall be amended by amending and restating in their
      entirety the following definitions:




"“ *Applicable
      Repayment Date* ”
means,
      with respect to each Loan made hereunder, the earlier of (i) the date occurring
      one day prior to the date which is one year from the date the initial Borrowing
      of such Loan was advanced, and (ii) the Termination Date. "




"“ *Impermissible
      Qualification* ”
means,
      relative to the opinion or certification of any independent public accountant
      as
      to any financial statement of a Borrower, any qualification or exception to
      such
      opinion or certification (i) which is of a “going concern” or similar nature,
      (ii) which relates to the limited scope of examination of matters relevant
      to
      such financial statement, or (iii) which relates to the treatment or
      classification of any item in such financial statement and which would require
      an adjustment to such item the effect of which would be to cause the Borrowers
      to be in violation of Section 7.15 hereof."







"“ *Indebtedness* ”
means,
      as to any Person, without duplication: (i) all obligations of such Person for
      borrowed money or evidenced by bonds, debentures, notes or similar instruments;
      (ii) all obligations of such Person for the deferred purchase price of Property
      or services (other than in respect of trade accounts payable arising in the
      ordinary course of business which are not past-due); (iii) all Capitalized
      Lease
      Obligations of such Person; (iv) all indebtedness of the kind referred to in
      (i)-(iii) and (v)-(vii) secured by a Lien on such Person's interest in Property,
      assets or revenues to the extent of the lesser of the value of such Person's
      interest in such Property that is subject to such Lien or the principal amount
      of such indebtedness but excluding any such indebtedness secured by a Lien
      on
      any Property or assets owned by others if (A) such Person holds only a leasehold
      interest or an easement, right-of-way, license or similar right of use or
      occupancy with respect to such Property or asset and (B) such Person has not
      assumed or become liable for the payment of such indebtedness; (v) all
      Guarantees issued by such Person of Indebtedness of another Person; (vi) all
      obligations of such Person, contingent or otherwise, in respect of any letters
      of credit (whether commercial or standby) or bankers’ acceptances, and (vii) all
      obligations of such Person under synthetic (and similar type) lease
      arrangements; *provided* that for
      purposes of calculating such Person’s Indebtedness under such synthetic (or
      similar type) lease arrangements, such lease arrangement shall be treated as
      if
      it were a Capitalized Lease."




"“ *Property* ”
means
      any property or asset, of any nature whatsoever, whether real, personal or
      mixed, tangible or intangible, and whether now owned or hereafter
      acquired."




"“ *Related
      Parties* ”
means,
      subject to the provisions of Section 11.8 with respect to any Person, such
      Person’s Affiliates and the directors, officers, employees, agents and advisors
      of such Person and of such Person’s Affiliates."




"“ *SEC
      Disclosure Documents* ”
means
      all reports on forms 10K, 10Q, and 8K filed by Nicor or Nicor Gas with the
      SEC
      prior to the Closing Date."




Section
      1.1 of the
      5-Year Credit Agreement shall be further amended by adding the following
      definitions:




"“ *Guaranty* ”
means
      the Guaranty dated as of December 22, 2005, as amended or supplemented from
      time
      to time, among Nicor, as guarantor, in favor of JPMorgan Chase Bank, N.A.,
      in
      its capacity as agent for the lenders to the 2 Year Term Loan
      Agreement."




"“ *ICC
      Permitted Investment* ”
means
      any investment permitted by subsection (a) of Section 340.50 of the rules of
      the
      Illinois Commerce Commission."




"“ *ICC
      Regulated Transaction* ”
means
      any transaction between Nicor Gas and Nicor or any wholly-owned subsidiary
      of
      Nicor that does not violate the applicable orders, rules and regulations of
      the
      Illinois Commerce Commission."




"“ *2
      Year Term Loan Agreement* ”
means
      the 2 Year Term Loan Agreement dated as of December 22, 2005, as amended or
      supplemented from time to time, by and among Tropical Shipping and Construction
      Company Limited, a Cayman Islands exempt company, as borrower, the financial
      institutions from time to time party thereto, and JPMorgan Chase Bank, N.A.,
      as
      administrative agent."




2





"“ *210-Day
      Facility Agreement* ”
means
      (i) the 210-Day Credit Agreement entered into October 26, 2006, as amended
      or
      supplemented from time to time, among Nicor Gas, the financial institutions
      party thereto, JPMorgan Chase Bank, N.A., as administrative agent, ABN AMRO
      Bank
      NV, as syndication agent, Wachovia Bank, N.A., The Bank of Tokyo-Mitsubishi
      UFJ,
      Ltd., Chicago Branch and The Bank of New York, as documentation agents, J.P.
      Morgan Securities Inc. and ABN AMRO Incorporated, as joint lead-arrangers and
      bookrunners and (ii) any successive agreements to the 210-Day Credit Agreement
      referred to in clause (i) above which are on substantially similar terms and
      are
      for substantially similar purposes as the credit agreement referred to in clause
      (i)."




2.03. Extensions . Section
      3.2 of the
      5-Year Credit Agreement shall be amended and restated in its entirety to read
      as
      follows:




"Section
      3.2  *Extensions* .




(a)  *Requests
      for Extension* .
      The
      Borrowers may, by notice to the Administrative Agent (which shall promptly
      notify the Lenders) not earlier than 45 days and not later than 35 days prior
      to
      each anniversary of the Closing Date (the “ *Annual
      Anniversary* ”),
      request that each Lender extend such Lender’s Termination Date for an additional
      year from the Termination Date then in effect hereunder (the “ *Existing
      Termination Date* ”).




(b)  *Lender
      Elections to Extend* .
      Each
      Lender, acting in its sole and individual discretion, shall, by notice to the
      Administrative Agent given not earlier than 30 days prior to the Annual
      Anniversary and not later than the date (the “ *Notice
      Date* ”)
      that
      is 20 days prior to the Annual Anniversary, advise the Administrative Agent
      whether or not such Lender agrees to such extension and each Lender that
      determines not to so extend its Commitment Termination Date (a “ *Non-Extending
      Lender* ”)
      shall
      notify the Administrative Agent of such fact promptly after such determination
      (but in any event no later than the Notice Date) and any Lender that does not
      so
      advise the Administrative Agent on or before the Notice Date shall be deemed
      to
      be a Non-Extending Lender. The election of any Lender to agree to such extension
      shall not obligate any other Lender to so agree.




(c)  *Notification
      by Administrative Agent* .
      The
      Administrative Agent shall notify the Borrowers of each Lender’s determination
      under this Section no later than the date 15 days prior to the Annual
      Anniversary (or, if such date is not a Business Day, on the next preceding
      Business Day).




(d)  *Additional
      Commitment Lenders* .
      The
      Borrowers shall have the right on or before the Annual Anniversary to replace
      each Non-Extending Lender with, and add as “Lenders” under this Agreement in
      place thereof, one or more Eligible Assignees (each, an “ *Additional
      Commitment Lender* ”)
      with
      the approval of the Administrative Agent (which approval shall not be
      unreasonably withheld). Each Additional Commitment Lender shall enter into
      an
      agreement in form and substance satisfactory to the Borrowers and the
      Administrative Agent pursuant to which such Additional Commitment Lender shall,
      effective as of the Existing Termination Date, undertake a Commitment (and,
      if
      any such Additional Commitment Lender is already a Lender, its Commitment shall
      be in addition to such Lender’s Commitment hereunder on such date).




3





(e)  *Minimum
      Extension Requirement* .
      If (and
      only if) the Required Lenders have agreed to extend their Termination Date,
      then, effective as of the Annual Anniversary, the Termination Date of each
      Extending Lender and of each Additional Commitment Lender shall be extended
      to
      the date falling one year after the Existing Termination Date (except that,
      if
      such date is not a Business Day, such Commitment Date as so extended shall
      be
      the next preceding Business Day) and each Additional Commitment Lender shall
      thereupon become a “Lender” for all purposes of this Agreement.




(f)  *Conditions
      to Effectiveness of Extensions* .
      Notwithstanding the foregoing, the extension of the Termination Date pursuant
      to
      this Section shall not be effective with respect to any Lender
      unless:




(i)  no
      Default or Event of Default shall have occurred and be continuing on the date
      of
      such extension and after giving effect thereto;




(ii)  the
      representations and warranties contained in this Agreement are true and correct
      on and as of the date of such extension and after giving effect thereto, as
      though made on and as of such date (or, if any such representation or warranty
      is expressly stated to have been made as of a specific date, as of such specific
      date);




(iii)  the
      Borrowers shall deliver a certified copy of their respective Board of Directors'
      resolutions authorizing such extension; and




(iv)  on
      or
      before the Termination Date of each Non-Extending Lender, (1) the Borrowers
      shall have paid in full the principal of and interest on all of the Loans made
      by such Non-Extending Lender to the Borrowers hereunder and (2) the Borrowers
      shall have paid in full all other Obligations owing to such Lender
      hereunder."




2.04 Representations
      and Warranties .
      The
      lead-in to Section
      5 of the
      5-Year Credit Agreement is hereby amended and restated in its entirety to read
      as follows:




" Section
      5  Each
      Borrower hereby represents and warrants to each Lender as to itself and, where
      the following representations and warranties apply to its Subsidiaries or
      Material Subsidiaries, as to each Subsidiary or Material Subsidiary, as
      applicable, of such Borrower, as follows:"




2.05. Government
      Regulation . Section
      5.9 of the
      5-Year Credit Agreement is hereby amended and restated in its entirety to read
      as follows:




"Section
      5.9  *Government
      Regulation.* Neither
      Borrower nor any Subsidiary of a Borrower is an “ *investment
      company* ”
within
      the meaning of the Investment Company Act of 1940, as amended."




2.06. Property
      and Liens . Section
      5.12 of the
      5-Year Credit Agreement is hereby amended and restated in its entirety to read
      as follows:




"Section
      5.12  *Ownership
      of Property; Liens.* Each
      Borrower and each Subsidiary of such Borrower owns good title to, or a valid
      leasehold interest in, or other enforceable


4





interest
      in, its Property to the extent owned or leased by it (except where the failure
      to have such title, a valid leasehold interest or other enforceable interest
      is
      not reasonably likely to have a Material Adverse Effect) free and clear of
      all
      Liens, except as permitted in Section 7.9."




2.07. Compliance
      with Agreements . Section
      5.13 of the
      5-Year Credit Agreement is hereby amended and restated in its entirety to read
      as follows:




"Section
      5.13  *Compliance
      with Agreements.* None
      of
      the execution and delivery of this Agreement and the Notes, the consummation
      of
      the transactions herein contemplated and compliance with the terms and
      provisions hereof will conflict with or result in a breach of, or require any
      consent under, the charter or by-laws of either of the Borrowers, or any
      applicable law or regulation, or any order, writ, injunction or decree of any
      court or Governmental Authority, or any Contractual Obligation to which either
      Borrower is a party or by which it is bound or to which it is subject, or
      constitute a default under any such Contractual Obligation, or result in the
      creation or imposition of any Lien upon any of the revenues or assets of either
      of the Borrowers pursuant to the terms of any such Contractual Obligation except
      as would not have a Material Adverse Effect."




2.08. ERISA . Section
      7.4 of the
      5-Year Credit Agreement is hereby amended and restated in its entirety to read
      as follows:




"Section
      7.4  *ERISA.* Each
      Borrower will, and will cause each of its Subsidiaries to, promptly pay and
      discharge all obligations and liabilities arising under ERISA of a character
      which if unpaid or unperformed is reasonably likely to result in the imposition
      of a Lien against any of its Properties, except to the extent the imposition
      of
      such Lien would not result in a Material Adverse Effect."




2.09. Financial
      Reports and Other Information . Section
      7.6(b) and Section
      7.6(d) of the
      5-Year Credit Agreement are here by amended and restated in its entirety to
      read
      as follows:




"Section
      7.6(b).




....




(b)  Each
      financial statement furnished to the Lenders pursuant to subsection (a) of
      this
      Section 7.6 shall be accompanied by a Compliance Certificate in the form of
      Exhibit B hereto signed by the Chief Financial Officer, Vice President -
      Controller, or Vice President - Treasurer of Nicor. Information required to
      be
      delivered pursuant to subsections (a), (d) and (e) of this Section 7.6 shall
      be
      deemed to have been delivered on the date on which a Borrower provides notice
      to
      the Administrative Agent (via email or otherwise) that such information has
      been
      posted on Nicor's website on the Internet at www.nicor.com, at
      www.sec.gov/edgar/searchedgar/webusers.htm or at another website identified
      in
      such notice and accessible by the Lenders without charge, *provided* that (i)
      such notice may be included in a Compliance Certificate in the form of Exhibit
      B
      and (ii) a Borrower shall deliver paper copies of the information required
      to be
      delivered pursuant to subsections (a), (d) and (e) of this Section 7.6 to any
      Lender that requests such delivery."




"Section
      7.6(d).




5





....




(d)  Promptly
      upon their becoming available, and without duplication of the other materials
      required to be delivered pursuant to this Agreement, each Borrower will deliver
      (via email or otherwise) to the Administrative Agent, with copies for each
      Lender copies of all registration statements and regular periodic reports,
      if
      any, which either Borrower shall have filed with the SEC (or any governmental
      agency substituted therefore) or any national securities exchange."




2.10. Lender
      Inspection Rights . Section
      7.7 of the
      5-Year Credit Agreement shall be amended and restated in its entirety to read
      as
      follows:




"Section
      7.7.  *Lender
      Inspection Rights.* For
      purposes of confirming compliance with the Credit Documents or after the
      occurrence and during the continuance of an Event of Default, upon reasonable
      notice from the Administrative Agent or the Required Lenders, Borrowers will,
      permit the Lenders (and such Persons as any Lender may designate) during normal
      business hours to visit and inspect, under Borrowers’ guidance, any of the
      Properties of Borrowers or any of their Material Subsidiaries, to examine all
      of
      their books of account, records, reports and other papers, to make copies and
      extracts therefrom, and to discuss their respective affairs, finances and
      accounts with their respective officers, employees and with their independent
      public accountants (and by this provision Borrowers authorize such accountants
      to discuss with the Lenders (and such Persons as any Lender may designate)
      the
      finances and affairs of Borrowers and their Material Subsidiaries) all at such
      reasonable times and as often as may be reasonably requested; provided, however,
      that except upon the occurrence and during the continuation of any Default
      or
      Event of Default, not more than one such visit and inspection may be conducted
      in any twelve month period. Prior to the occurrence of an Event of Default,
      the
      Borrowers shall only be required to pay the costs and expenses of professionals
      retained by the Administrative Agent in connection with any such visit or
      inspection. After the occurrence of an Event of Default, the Borrowers shall
      be
      obligated to pay all reasonable costs and expenses incurred by the
      Administrative Agent and the Lenders in connection with such visitations and
      inspections. The Borrowers shall receive advance notice of any proposed
      discussion with such accountants and shall have the right to participate
      therein."




2.11. Liens . Section
      7.9 of the
      5-Year Credit Agreement shall be amended and restated in its entirety to read
      as
      follows:




"Section
      7.9  *Liens.* Neither
      Borrower will, nor will it permit any of its Material Subsidiaries to, create,
      incur, permit or suffer to exist any Lien on any of its Property, whether now
      owned or hereafter acquired by such Borrower or any Material Subsidiary of
      such
      Borrower; *provided* , *however* ,
      that
      this Section 7.9 shall not apply to or operate to prevent:




(a)  Liens
      arising by operation of law which are incurred in the ordinary course of
      business which do not in the aggregate materially detract from the value of
      the
      Property subject thereto or materially impair the use thereof in the operation
      of the business of Borrower or any of its Material Subsidiaries;




(b)  Liens
      for
      taxes or assessments or other government charges or levies on a Borrower or
      any
      Material Subsidiary of a Borrower or their respective Properties which




6


are
        not
        past due or which are being contested in good faith by appropriate proceedings
        and for which reserves in conformity with GAAP have been provided on the
        books
        of a Borrower; *provided* that the
        aggregate amount of liabilities (including interest and penalties, if any)
        of
        the Borrowers and their Material Subsidiaries secured by such Liens shall
        not
        exceed $20,000,000 at any one time outstanding;




(c)  Liens
      arising out of judgments or awards against a Borrower or any Material Subsidiary
      of a Borrower, or in connection with surety or appeal bonds in connection with
      bonding such judgments or awards, the time for appeal from which or petition
      for
      rehearing of which shall not have expired or with respect to which such Borrower
      or such Material Subsidiary shall be prosecuting an appeal or proceeding for
      review, and with respect to which it shall have obtained a stay of execution
      pending such appeal or proceeding for review; *provided* that the
      aggregate amount of liabilities (including interest and penalties, if any)
      of
      Borrower and its Material Subsidiaries secured by such Liens shall not exceed
      $20,000,000 at any one time outstanding;




(d)  Survey
      exceptions or encumbrances, easements or reservations, or rights of others
      for
      rights-of-way, utilities and other similar purposes, or zoning or other
      restrictions as to the use of real Properties which do not materially impair
      their use in the operation of the business of a Borrower or any Material
      Subsidiary of a Borrower;




(e)  Liens
      existing on the date hereof and Liens granted pursuant to the terms of the
      Nicor
      Gas Indenture;




(f)  Liens
      securing Indebtedness and other obligations; provided that such Liens permitted
      by this paragraph (f) shall only be permitted to the extent the aggregate amount
      of Indebtedness and other obligations secured by all such Liens does not exceed
      ten percent (10%) of the difference between (A) Consolidated Assets as reflected
      on the most recent balance sheet delivered by Nicor pursuant to Section 7.6,
      minus (B) the amount of Indebtedness then outstanding under the Nicor Gas
      Indenture;




(g)  Liens
      in
      favor of carriers, warehousemen, mechanics, materialmen and landlords granted
      in
      the ordinary course of business for amounts not overdue or being diligently
      contested in good faith by appropriate proceedings and for which adequate
      reserves in accordance with GAAP shall have been set aside on its
      books;




(h)  Liens
      incurred or deposits made in the ordinary course of business in connection
      with
      worker’s compensation, unemployment insurance or other forms of governmental
      insurance or benefits;




(i)  Liens
      with respect to any surplus assets leased by either Borrower or any of its
      Material Subsidiaries;




(j)  Liens
      on
      any Properties or assets owned by a Person other than either Borrower or any
      Material Subsidiary of either Borrower if such Borrower or a Material Subsidiary
      of such Borrower holds only leasehold interests or easements, rights-of-way,
      licenses or similar rights of use or occupancy with respect to such Properties
      or assets;




(k)  Any
      extension, renewal or replacement (or successive extensions, renewals or
      replacements) in whole or in part of any Lien referred to in the foregoing
      paragraphs (a) through (j), inclusive; *provided* , *however* ,
      that
      the principal amount of




7


Indebtedness
        of either Borrower or any of its Material Subsidiaries secured thereby shall
        not
        exceed the principal amount of Indebtedness of such Borrower or any of its
        Material Subsidiaries so secured at the time of such extension, renewal or
        replacement, and that such extension, renewal or replacement shall be limited
        to
        the Property of either Borrower or any of its Material Subsidiaries which
        was
        subject to the Lien so extended, renewed or replaced;




*provided* ,
      that,
      except as may be created under the Nicor Gas Indenture, the foregoing paragraphs
      shall not be deemed under any circumstance to permit a Lien to exist on (i)
      any
      capital stock or other equity interests of Nicor Gas or (ii) Nicor Gas’ natural
      gas inventory or any receivables arising from the sale of such
      inventory.




Any
      Lien
      which when incurred or permitted to exist complies with the requirements of
      paragraphs (a) through (k) above may continue to exist, and shall be permitted
      hereunder, notwithstanding that such Lien if incurred thereafter would not
      comply with such requirement."




2.12. Investments,
      Acquisitions, Loans, Advances and Guaranties . Section
      7.13 of the
      5-Year Credit Agreement shall be amended and restated in its entirety to read
      as
      follows:




"Section
      7.13  *Investments,
      Acquisitions, Loans, Advances and Guaranties.* Neither
      Borrower will, nor will it permit any Material Subsidiary of such Borrower
      to,
      directly or indirectly, make, retain or have outstanding any investments
      (whether through purchase of stock or obligations or otherwise) in, or loans
      or
      advances to, any other Person, or acquire all or any substantial part of the
      assets or business of any other Person or division thereof, or be or become
      liable as endorser, guarantor, surety or otherwise (such as liability as a
      general partner) for any debt, obligation or undertaking of any other Person,
      or
      otherwise agree to provide funds for payment of the obligations of another,
      or
      supply funds thereto or invest therein or otherwise assure a creditor of another
      against loss, or apply for or become liable to the issuer of a letter of credit
      which supports an obligation of another, or subordinate any claim or demand
      it
      may have to the claim or demand of any other Person (cumulatively, all of the
      foregoing “Investments”); provided, however, that the foregoing provisions shall
      not apply to nor operate to prevent:




(a)  ICC
      Permitted Investments;




(b)  ownership
      of stock, obligations or securities received in settlement of debts owing to
      a
      Borrower or any Subsidiary;




(c)  endorsements
      of negotiable instruments for collection in the ordinary course of
      business;




(d)  loans
      and
      advances to employees in the ordinary course of business for travel, relocation,
      and similar purposes;




(e)  Investments
      (i) in or with respect to either Borrower or any Subsidiary of either Borrower,
      including intercompany loans, or (ii) existing on the Closing Date;




(f)  Investments
      constituting (i) accounts receivable arising, (ii) trade debt granted, or (iii)
      deposits made in connection with the purchase price of goods or services, in
      each case in the ordinary course of business;




8





(g)  Investments
      in Persons engaged in substantially the same lines of business as the Borrowers
      or any of their Subsidiaries so long as, unless consented to by the Required
      Lenders, (i) no downgrade in the S&P Rating or Moody’s Rating would occur as
      a result of the consummation of such Investment, (ii) if such Investment is
      for
      the purpose of acquiring another Person, the Board of Directors (or similar
      governing body) of such Person being acquired has approved being so acquired,
      and (iii) no Default or Event of Default has occurred and is continuing at
      the
      time of, or would occur as a result of, such Investment; and




(h)  Guarantees
      by either Borrower or any of their respective Subsidiaries of any Indebtedness
      (so long as such Indebtedness is permitted pursuant to Section 7.14) or other
      obligations of either Borrower or any of their respective
      Subsidiaries;




(i)  Investments,
      whether directly or indirectly through one or more Subsidiaries, in Triton
      Container Investments LLC, a cargo container leasing business, made after the
      Closing Date in an aggregate amount not to exceed $20,000,000 in any one year
      (with the Closing Date and each anniversary thereof being deemed the first
      day
      of a year for calculating compliance with this provision); and




(j)  other
      Investments in addition to those set forth above not to exceed an aggregate
      amount of (i) $50,000,000 in any one year (with the Closing Date and each
      anniversary thereof being deemed the first day of a year for calculating
      compliance with this provision), and (ii) $100,000,000 during the term of this
      Agreement.




Any
      Investment which when made complies with the requirements of paragraphs (a)
      through (i) above may continue to be held notwithstanding that such Investment
      if made thereafter would not comply with such requirements.




In
      determining the amount of investments, acquisitions, loans, advances and
      guarantees permitted under this Section 7.13, investments and acquisitions
      shall
      always be taken at the original cost thereof (regardless of any subsequent
      appreciation or depreciation therein), loans and advances shall be taken at
      the
      principal amount thereof then remaining unpaid, and guarantees shall be taken
      at
      the amount of obligations guaranteed thereby."




2.13. Restrictions
      on Indebtedness . Section
      7.14 of the
      5-Year Credit Agreement shall be amended and restated in its entirety to read
      as
      follows:




"Section
      7.14  *Restrictions
      on Indebtedness.* Neither
      Borrower will, nor will it permit any of its Material Subsidiaries to, issue,
      incur, assume, create, become liable for, contingently or otherwise, or have
      outstanding any Indebtedness, *provided* that the
      foregoing provisions shall not restrict nor operate to prevent the following
      Indebtedness:




(a)  the
      Obligations;




(b)  any
      other
      Indebtedness so long as after giving effect to the incurrence thereof the
      Borrowers shall be in compliance with the Leverage Ratio set forth in Section
      7.15."




2.14. Leverage
      Ratio . Section
      7.15 of the
      5-Year Credit Agreement shall be amended and restated in its entirety to read
      as
      follows:




9










"Section
      7.15  *Leverage
      Ratio.* Nicor
      will not at the end of any fiscal quarter permit the ratio of its Consolidated
      Indebtedness to its Capital to exceed 0:70 to 1:00.




For
      the
      purposes of the calculation of the ratio of Nicor's Consolidated Indebtedness
      to
      Nicor's Capital, (1) any non-cash effects resulting from adoption of the
      proposed “Statement of Financial Accounting Standards dated March 31, 2006:
      Employers’ Accounting for Defined Pension and other Postretirement Plans, an
      amendment of FASB Statements No. 87, 88, 106, and 132(R)" shall be excluded;
      (2)
      any hybrid equity securities, meaning any securities issued by Nicor and/or
      its
      Subsidiaries or a financing vehicle of Nicor and/or its Subsidiaries that (i)
      are classified as possessing a minimum of “intermediate equity content” by
      S&P, Basket C equity credit by Moody’s, and 50% equity credit by Fitch and
      (ii) require no repayments or prepayments and no mandatory redemptions or
      repurchases, in each case, prior to at least 91 days after the later of the
      termination of the Commitments and the repayment in full of the Loans and all
      other amounts due hereunder, shall be excluded from Nicor's Consolidated
      Indebtedness and (3) any mandatorily convertible securities, meaning any
      mandatorily convertible equity-linked securities issued by Nicor and/or its
      Subsidiaries, so long as the terms of such securities require no repayments
      or
      prepayments and no mandatory redemptions or repurchases, in each case prior
      to
      at least 91 days after the later of the termination of the Commitments and
      the
      repayment in full of the Loans and all other amounts due hereunder, shall be
      excluded from Nicor's Consolidated Indebtedness."




2.15. Dividends
      and Other Shareholder Distributions . Section
      7.17(b) of the
      5-Year Credit Agreement shall be amended and restated in its entirety to read
      as
      follows:




"Section
      7.17  *Dividends
      and Other Shareholder Distributions.*




....


(b)  Except
      as
      set forth on Schedule 7.17, neither Borrower will permit any of its Material
      Subsidiaries, directly or indirectly, to create or otherwise cause or suffer
      to
      exist or become effective any consensual encumbrance or restriction of any
      kind
      on the ability of any such Material Subsidiary to: (1) pay dividends or make
      any
      other distribution on any of such Material Subsidiary’s capital stock owned by a
      Borrower or any Material Subsidiary of a Borrower, (2) pay any Indebtedness
      owed
      to a Borrower or any other Material Subsidiary, (3) make loans or advances
      to a
      Borrower or any other Material Subsidiary, or (4) transfer any of its Property
      or assets to a Borrower or any other Material Subsidiary, except for such
      encumbrances or restrictions existing under or by reason of:




(a)  customary
      non-assignment provisions of any contract and customary provisions restricting
      assignment or subletting in any lease governing a leasehold interest of any
      Material Subsidiary; and




(b)  customary
      restrictions contained in any consensual Liens that are permitted pursuant
      to
      Section 7.9."




2.16. No
      Negative Pledges . Section
      7.18 of the
      5-Year Credit Agreement shall be amended and restated in its entirety to read
      as
      follows:




10










"Section
      7.18  *No
      Negative Pledges.* Except
      as
      set forth on Schedule 7.17, the Borrowers will not, and will not permit any
      of
      their Material Subsidiaries to enter into or suffer to exist any agreement
      (except the Credit Documents) prohibiting the creation or assumption of any
      security interest upon its properties or assets, whether now owned or hereafter
      acquired by the Borrowers or their Material Subsidiaries, as applicable; *provided* , *however* ,
      in the
      case of a consensual Lien on assets or property that is permitted pursuant
      to
      Section 7.9, the Lien holder may, solely with respect of the assets or property
      to which such Lien attaches, contract for and receive a negative pledge with
      respect thereto and the proceeds thereof."




2.17. Transactions
      with Affiliates . Section
      7.19 of the
      5-Year Credit Agreement shall be amended and restated in its entirety to read
      as
      follows:




"Section
      7.19  *Transactions
      with Affiliates.* Neither
      Borrower will, nor will they permit any of their Subsidiaries to, enter into
      or
      be a party to any material transaction or arrangement with any Affiliate of
      such
      Person, including without limitation, for purchase from, sale to or exchange
      of
      Property with, for merger or consolidation with or into, or the rendering of
      any
      service by or for, any Affiliate, except (i) pursuant to the reasonable
      requirements of a Borrower’s or such Subsidiary’s business and upon terms no
      less favorable to a Borrower or such Subsidiary than could be obtained in a
      similar transaction involving a third-party, (ii) any ICC Regulated Transaction,
      (iii) to the extent such material transaction or arrangement would not result
      in
      a Material Adverse Effect, or (iv) as otherwise permitted in this
      Agreement."




2.18. Non-Business
      Day . Section
      11.2 of the
      5-Year Credit Agreement shall be amended and restated in its entirety to read
      as
      follows:




"Section
      11.2  *Non-Business
      Day* .
      Except
      as otherwise expressly provided in this Agreement, if any payment of principal
      or interest on any Loan or of any other Obligation shall fall due on a day
      which
      is not a Business Day, interest or fees (as applicable) at the rate, if any,
      such Loan or other Obligation bears for the period prior to maturity shall
      continue to accrue on such Obligation from the stated due date thereof to and
      including the next succeeding Business Day, on which the same shall be
      payable.




2.19.
      Notices. Section 11.6(a)(i) of the 5-Year Credit Agreement shall be amended
      and
      restated in its entirety to read as follows:




"Section
      11.6(a)   *Notices
      Generally* .




....




(i)  1844
      Ferry Road; Naperville, IL 60563


Attention:
      Treasurer


Fax:
      630-983-3810


Confirm
      No.: 630-388-2800


...."





2.20 Modified
      Compliance Certificate . Exhibit
      B shall be
      amended and restated in its entirety as set forth on Schedule 1.




11





2.21. Amended
      Schedule 5.2. Schedule
      5.2 ( *Material
      Subsidiaries)* shall
      be
      amended and restated in its entirety as set forth on Schedule 2.




2.22. Permitted
      Investments . Schedule
      7.13 ( *Permitted
      Investments* )
      shall
      be deleted in its entirety from the 5-Year Credit Agreement.




2.23. Amended
      Schedule 7.17 . Schedule
      7.17 ( *Restrictions
      on Distributions and Existing Negative Pledges* )
      shall
      be amended and restated in its entirety as set forth on Schedule 3.




Section
      3.  Representations
      and Warranties .
      Each
      Borrower represents and warrants to the Lenders and the Administrative Agent
      that, after giving effect to this Amendment, (a) the representations and
      warranties set forth in Section
      5 of the
      5-Year Credit Agreement are true and complete on the date hereof as if made
      on
      and as of the date hereof (or, if any such representation or warranty is
      expressly stated to have been made as of a specific date, such representation
      or
      warranty shall be true and correct as of such specific date), and as if each
      reference in said Section
      5 to "this
      Agreement" included reference to this Amendment and (b) no Default or Event
      of
      Default has occurred and is continuing.




Section
      4.  Conditions
      Precedent .
      The
      amendments set forth in Section
      2 hereof
      shall become effective, as of the date hereof, upon the receipt by the
      Administrative Agent of (i) a legal opinion from counsel to the Borrower
      addressed to the Administrative Agent and the Lenders and (ii) counterparts
      of
      this Amendment executed by each Borrower, the Required Lenders and the
      Administrative Agent.




Section
      5.  Waiver .
      The
      Required Lenders hereby waive all Defaults and Events of Default, if any, which
      may have occurred prior to the date of this Amendment resulting from (i) a
      failure by either Borrower to deliver documents to the Administrative Agent
      or
      the Lenders in accordance with Section 7.6 of the 5-Year Credit Agreement as
      in
      effect prior to this Amendment, (ii) any condition that existed or action or
      inaction by either Borrower that was not or may not have been in compliance
      with
      Sections 7.9, 7.13(e), 7.14(b), 7.17(b) or 7.18 of the 5-Year Credit Agreement
      as in effect prior to this Amendment, but would have been in compliance with
      the
      5-Year Credit Agreement as in effect on or after the date hereof, (iii) any
      inaccuracy in any representation or warranty made by either Borrower prior
      to
      this Amendment as to its compliance with Sections 7.6, 7.9, 7.13(e), 7.14(b),
      7.17(b) or 7.18 of the 5-Year Credit Agreement as in effect prior to this
      Amendment, (iv) any inaccuracy in the representation and warranty set forth
      in
      Section 5.12 of the 5-Year Credit Agreement as in effect prior to this Amendment
      or (v) a failure by either Borrower to provide notice of any such failure,
      condition, action, inaction or inaccuracy referred to in clauses (i) - (iv)
      above.




Section
      6.  Miscellaneous .
      Except
      as herein provided, the 5-Year Credit Agreement shall remain unchanged and
      in
      full force and effect. This Amendment may be executed in any number of
      counterparts, all of which taken together shall constitute one and the same
      amendatory instrument and any of the parties hereto may execute this Amendment
      by signing any such counterpart. Delivery of an executed counterpart of a
      signature page of this Amendment by facsimile (or other electronic transmission)
      shall be effective as delivery of a manually executed counterparty hereof.
      This
      Amendment shall be governed by, and construed in accordance with, the law of
      the
      State of New York, United States of America, without giving effect to principles
      of conflicts of laws (other than Section 5-1401 of the New York General
      Obligations Law).




12





IN
      WITNESS WHEREOF, the parties hereto have caused this Amendment to the 5-Year
      Credit Agreement to be duly executed and delivered as of the day and year first
      above written.




NORTHERN
      ILLINOIS GAS COMPANY ,


as
      Borrower





By: /s/
      GERALD P.
      O'CONNOR   Name: Gerald
      P.
      O'Connor


Title:
      Vice President - Treasurer







NICOR
      INC.,


as
      Borrower








By: /s/
      GERALD P. O'CONNOR  Name:
      Gerald P. O'Connor


Title:
      Vice President - Treasurer




















SIGNATURE
      PAGE TO THE 5-YEAR CREDIT AGREEMENT AMENDMENT













**JPMORGAN
      CHASE BANK, N. A.,**


in
      its
      individual capacity as a Lender and as Administrative Agent








By: /s/
      GABRIEL J. SIMON


Name: Gabriel
      J. Simon


Title: Assistant
      Vice President




















BANK
          SIGNATURE PAGE TO 5-YEAR CREDIT AGREEMENT AMENDMENT








**ABN
      AMRO BANK N. V.**








By: /s/ CHARLES
      F. RANDOLPH


Name: Charles
      F.
      Randolph


Title: Managing
      Director








By: /s/
      ECE
      Bennett


Name: Ece
      Bennett


Title: Director




















BANK
          SIGNATURE PAGE TO 5-YEAR CREDIT AGREEMENT AMENDMENT








**THE
      BANK OF TOKYO-MITSUBISHI UFJ, LTD., CHICAGO BRANCH (F/K/A THE BANK OF
      TOKYO-MITSUBISHI, LTD., CHICAGO BRANCH)**








By: /s/
      TSUGUYUKI UMENE


Name: Tsuguyuki
      Umene


Title: Deputy
      General Manager




















BANK
          SIGNATURE PAGE TO 5-YEAR CREDIT AGREEMENT AMENDMENT








**WACHOVIA
      BANK, N. A.**








By: /s/
      SHAWN YOUNG


Name: Shawn
      Young


Title: Vice
      President




















BANK
          SIGNATURE PAGE TO 5-YEAR CREDIT AGREEMENT AMENDMENT








**U.S.
      BANK NATIONAL ASSOCIATION**








By: /s/ JAMES
      N.
      DEVRIES


Name: James
      N. Devries


Title: Senior
      Vice
      President




















BANK
          SIGNATURE PAGE TO 5-YEAR CREDIT AGREEMENT AMENDMENT








**THE
      BANK OF NEW YORK**








By: /s/
      RICHARD K. FRONAPFEL, JR.


Name: Richard
      K. Fronapfel,
      Jr.


Title: Vice
      President




















BANK
          SIGNATURE PAGE TO 5-YEAR CREDIT AGREEMENT AMENDMENT








**BANCO
      BILBAO VIZCAYA**


**ARGENTARIA
      S.A.**








By: /s/
      MARIA T.
      VIZAN


Name: Maria
      T.
      Vizan


Title: Vice
      President - Global Corporate Banking








By: /s/
      JOHN
      MARTINI


Name: John
      Martini


Title: Vice
      President - Corporate
      Banking




















BANK
          SIGNATURE PAGE TO 5-YEAR CREDIT AGREEMENT AMENDMENT








**WELLS
      FARGO BANK, NATIONAL**


**ASSOCIATION**








By: /s/
      CHARLES W.
      REED


Name: Charles
      W.
      Reed


Title: Vice
      President




















BANK
          SIGNATURE PAGE TO 5-YEAR CREDIT AGREEMENT AMENDMENT








**SUNTRUST
      BANK**








By: /s/
      YANN
      PIRIO


Name: Yann
      Pirio


Title: Vice
      President




















BANK
          SIGNATURE PAGE TO 5-YEAR CREDIT AGREEMENT AMENDMENT








**MIZUHO
      CORPORATE BANK, LTD.**








By: /s/
      RAYMOND
      VENTURA


Name: Raymond
      Ventura


Title: Deputy
      General
      Manager


BANK
          SIGNATURE PAGE TO 5-YEAR CREDIT AGREEMENT AMENDMENT








**FIFTH
      THIRD BANK (CHICAGO),**


**A
      MICHIGAN BANKING CORPORATION**








By: /s/
      KIM PUSZCZEWICZ


Name: Kim
      Puszczewicz


Title: Vice
      President


















BANK
            SIGNATURE PAGE TO 5-YEAR CREDIT AGREEMENT AMENDMENT


SECOND AMENDMENT TO THE 5-YEAR CREDIT AGREEMENT ****









**SCHEDULE
      1 TO THE AMENDMENT**




**MODIFIED
      EXHIBIT B**


**COMPLIANCE
      CERTIFICATE**




COMPLIANCE
      CERTIFICATE




This
      Compliance Certificate is furnished to JPMorgan Chase Bank, N.A., as
      Administrative Agent pursuant to the Credit Agreement dated as of September
      13,
      2005, among Northern Illinois Gas Company, an Illinois corporation
      (“ *Nicor
      Gas* ”),
      and
      Nicor Inc., an Illinois corporation (“ *Nicor* ”;
      Nicor
      Gas and Nicor are each referred to herein as a " *Borrower* "
      and
      collectively as " *Borrowers* ")
      JPMorgan Chase Bank, N.A., as Administrative Agent and the financial
      institutions party thereto (as amended, supplemented or otherwise modified
      from
      time to time, the “ *Credit
      Agreement* ”).
      Unless otherwise defined herein, the terms used in this Compliance Certificate
      have the meanings ascribed thereto in the Credit Agreement.




THE
      UNDERSIGNED HEREBY CERTIFIES THAT:




1.  I
      am the
      duly elected or appointed ___________________of Nicor;




2.  I
      have
      reviewed the terms of the Credit Agreement and I have made, or have caused
      to be
      made under my supervision, a detailed review of the transactions and conditions
      of Nicor and its Subsidiaries during the accounting period covered by the
      financial statements (which financial statements have been posted on Nicor's
      website on the Internet at www.nicor.com);




3.  The
      examinations described in paragraph 2 did not disclose, and I have no knowledge
      of, the existence of any condition or event which constitutes a Default or
      an
      Event of Default during or at the end of the accounting period covered by the
      Borrowers' financial statements for the year/quarter end (which financial
      statements have been posted on Nicor's website on the Internet at www.nicor.com)
      or as of the date of this Certificate, except as set forth below;
      and




4.  Schedule
      1 attached hereto sets forth financial data and computations evidencing
      compliance with certain covenants of the Credit Agreement, all of which data
      and
      computations are true, complete and correct. All computations are made in
      accordance with the terms of the Credit Agreement.




Described
      below are the exceptions, if any, to paragraph 3 listing, in detail, the nature
      of the condition or event, the period during which it has existed and the action
      which the Borrower has taken, is taking, or proposes to take with respect to
      each such condition or event:























The
      foregoing certifications, together with the computations set forth in Schedule
      1
      hereto are made and delivered this ___________day of __________,
      200_.












**SCHEDULE
      1 TO COMPLIANCE CERTIFICATE**




Compliance
      Calculations for Credit Agreement




**CALCULATION
      AS OF ________ __, 200_**









A.Leverage
                Ratio (Section 7.15)1.Consolidated
                Net Worth
            $2.Consolidated
                Indebtedness
            $3.Capital
                (Line A1 plus Line A2)
            $4.Leverage
                Ratio
            :1.00
            (ratio
                of Line A2 to Line A3 not to exceed 0.70:1.00)










**SCHEDULE
      2 TO THE AMENDMENT**









**AMENDED
      SCHEDULE 5.2**









**MATERIAL
      SUBSIDIARIES**




Subsidiary
                Name
            Place
                of Origin
            OwnershipNorthern
                Illinois Gas Company d/b/a Nicor Gas Company
            Illinois
            Wholly
              
              owned
                by
              
              Nicor
                Inc.Birdsall
                Inc.
            Florida
            Wholly
              
              owned
                by
              
              Nicor
                Inc.Tropical
                Shipping and Construction Company Limited
            Cayman
                Islands
            Wholly
                owned by Birdsall Inc.










**SCHEDULE
      3 TO THE AMENDMENT**









**AMENDED
      SCHEDULE 7.17**









RESTRICTIONS
      ON DISTRIBUTIONS AND EXISTING NEGATIVE PLEDGES














Refer
      to
      (i) Nicor Gas Indenture as defined in Section 1, (ii) the 210-Day Facility
      Agreement as defined in Section 1, (iii) the 2 Year Term Loan Agreement as
      defined in Section 1 and (iv) the Guaranty as defined in Section 1.