<PAGE>   1
                                                                   EXHIBIT 10(u)

                           REVOLVING CREDIT AGREEMENT

                                  BY AND AMONG


                               ENERGYSOUTH, INC.,
                                  AS BORROWER,


                                       AND


                          AMSOUTH BANK, N.A., AS AGENT,


                                       AND


                        AmSOUTH BANK, N.A., REGIONS BANK,
                    WHITNEY NATIONAL BANK, SOUTH ALABAMA BANK
                     SOUTHTRUST BANK, N.A., AND COMMONWEALTH
                                 NATIONAL BANK,

                                   AS LENDERS


                                      * * *

                                   $20,000,000

                                      * * *

                               SEPTEMBER 30, 1999


<PAGE>   2


                           REVOLVING CREDIT AGREEMENT

         This Revolving Credit Agreement is entered into as of the 30th day of
September, 1999, by and among EnergySouth, Inc., as Borrower ("Borrower"),
AmSouth Bank, N.A., as agent for Lenders to the extent and in the manner
provided in Article VIII below ("'Agent"), and AmSouth Bank, N.A., Regions Bank,
Whitney National Bank, South Alabama Bank, SouthTrust Bank, N.A., and
Commonwealth National Bank, as Lenders (collectively, "Lenders").

                              W I T N E S S E T H:

         WHEREAS, Borrower has requested that Lenders enter into this Revolving
Credit Agreement to provide for a revolving & edit facility for lending to
Borrower; and

         WHEREAS, Lenders have agreed to do so upon the terms and conditions
hereinafter set forth.

         NOW, THEREFORE, in consideration of the mutual promises herein
contained, and for other valuable consideration, the parties hereto agree as
follows:

                                   ARTICLE I
                              DEFINITIONS OF TERMS

         For the purposes of this Agreement, unless the context otherwise
requires, the following terms shall have the respective meanings assigned to
them in this Article I or in the section or recital referred to below:

         Section 1.01. "Advance" shall mean the disbursement by the Agent of a
sum or sums loaned to Borrower pursuant to this Agreement.

         Section 1.02. "Affiliate" shall mean any Person (1) which directly or
indirectly controls, or is controlled by, or is under common control with,
another Person or its Subsidiary; (2) which directly or indirectly beneficially
owns or holds five percent (5%) or more of any class of voting stock of another
Person or its Subsidiary; or (3) five percent (5%) or more of the voting stock
of which is directly or indirectly beneficially owned or held by another Person
or its Subsidiary. The term "control" means the possession, - directly
or-indirectly, of the power to direct or cause the direction of the management
and policies of a Person, whether through the ownership of voting securities, by
contract, or otherwise.


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<PAGE>   3


         Section 1.03. "Agent" shall have the meaning assigned to such term in
the preamble hereof.

         Section 1.04. "Agreement" or "this Agreement" shall mean this Revolving
Credit Agreement as the same may be amended or modified from time to time.

         Section 1.05. "AmSouth Bank" shall mean AmSouth Bank, N.A., a national
banking association.

         Section 1.06. "Applicable Rate of Interest" shall mean the rate of
interest designated in accordance with Section 3.02 hereof.

         Section 1.07. "Borrower" shall have the meaning assigned to such term
in the preamble hereof.

         Section 1.08. "Borrowing Account" shall mean a demand deposit account
in AmSouth Bank in the name of, and under the control of, Borrower.

         Section 1.09. "Borrowing Date" shall mean any date specified in a
Request for Advance delivered in accordance with the provisions of Section
2.02(a) as a date on which Borrower requests an Advance hereunder.

         Section 1.10. "Business-Day" shall mean a day on which banks are open
for business in Mobile, Alabama.

         Section 1.11. "Commitment" shall mean the obligation, of each Lender to
extend credit to Borrower under this Agreement in an aggregate principal amount
not to exceed such Lender's Committed Sum.

         Section 1.12. "Commitment Period " shall mean the period beginning on
the date hereof and ending on the Commitment Termination Date.

         Section 1.13. "Commitment Termination Date" shall mean the earlier of
(i) January 31, 2001 or, if such date is not a Business Day, the Business Day
next succeeding such date, unless the Lenders and Borrower shall agree in
writing by January 31, 2000 to the extension of the date of payment of the
indebtedness evidenced by the Note for one additional period of one (1) year, in
which event the date of payment of indebtedness evidenced by the Note, as
thereby extended, shall be the Commitment Termination Date, or (ii) date on
which the Commitment is terminated by either Borrower or Lenders pursuant to the
provisions hereof.


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         Section 1.14. "Committed Sum" shall mean, with respect to a Lender, the
amount set forth below opposite the name of such Lender:

<TABLE>
<S>                    <C>                                 <C>
                       AmSouth Bank           -            $   7,000,000.00
                       Regions Bank           -                5,000,000.00
                       Whitney Bank           -                5,000,000.00
                       South Alabama Bank     -                2,000,000.00
                       SouthTrust Bank        -                  900,000.00
                       Commonwealth Bank      -                  100,000.00
</TABLE>

         Section 1.15. "Commonwealth Bank" shall mean Commonwealth National
Bank, a national banking association.

         Section 1.16. "Debtor Law" shall mean any of, and "Debtor Laws" means
all of the applicable liquidation, conservatorship, bankruptcy, moratorium,
arrangement, receivership, insolvency, reorganization or similar laws of any
jurisdiction from time to time in effect affecting the rights of creditors
generally.

         Section 1.17. "Default" shall mean any of the events specified in
Article VII, regardless of whether there shall have occurred any passage of time
or giving of notice or both that would be necessary in order to constitute such
event an Event of Default.

         Section 1.18. "Event of Default" shall have the meaning assigned to
such term in Section 7.01.

         Section 1.19. "Governmental Authority" shall mean any government (or
any political subdivision or jurisdiction thereof), court, bureau, agency or
other governmental authority having jurisdiction over either Borrower or any of
its business, operations or properties.

         Section 1.20. "Indebtedness" shall mean all long-term debt listed in
Note 3 to Borrower's Consolidated Financial Statements contained in Borrower's
Annual Report on Form 10K for year ended September 30, 1998.

         Section 1.21. "Lenders" shall have the meaning assigned to such term in
the preamble hereof.

         Section 1.22. "LIBOR" shall mean a fluctuating rate of interest equal
to the average offered rate in the London Interbank Market for deposits in U.S.
dollars for a one-month period, as reported in the Money Rates section of The
Wall Street Journal.


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<PAGE>   5


         Section l.23. "Loan Documents" shall mean this Agreement and the Note
and all other documents executed by Borrower in connection therewith.

         Section 1.24. "Loans" shall mean the aggregate unpaid principal balance
of all Advances Loans; each Advance, individually, a "Loan".

         Section 1.25. "Maximum Rate" shall mean, on any day, the highest
nonusurious rate of interest permitted by applicable law on such day that at any
time, or from time to time, may be contracted for, taken, reserved, charged or
received on the Indebtedness evidenced by the Notes under the laws which are
presently in effect of the United States of America and the State of Alabama
applicable to the holders of the Notes and such Indebtedness or, to the extent
permitted by law, under such applicable laws of the United States of America and
the State of Alabama which may hereafter be in effect and which allow a higher
maximum nonusurious interest rate than applicable laws now allow.

         Section 1.26. "Note" shall mean the promissory note executed by
Borrower and delivered pursuant to the terms of this Agreement, together with
any renewals, extensions or modifications thereof.

         Section 1.27. "Obligations" shall mean:

         (a) all present and future indebtedness, obligations and liabilities of
Borrower to Agent and Lenders arising pursuant to this Agreement, regardless of
whether such indebtedness, obligations and liabilities are direct, indirect,
fixed, contingent, joint, several, or joint and several;

         (b) all present and future indebtedness, obligations and liabilities of
Borrower to Lenders arising pursuant to or represented by the Note and all
interest accruing thereon, and reasonable attorneys' fees incurred in the
enforcement or collection thereof;

         (c) all present and future indebtedness, obligations and liabilities of
Borrower evidenced by or arising pursuant to any of the Loan Documents; and

         (d) all renewals, extensions, modifications and refundings of the
indebtedness referred to in the foregoing clauses, or any part thereof.

         Section 1.28. "Percentage" shall mean, with respect to each Lender, the
percentage set forth below opposite the name of such Lender but as it may be
changed from time pursuant to Subsection 2.02(c):




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<TABLE>
<S>                    <C>                             <C>
                       AmSouth Bank           -         35% (.35)
                       Regions Bank           -         25% (.25)
                       Whitney Bank           -         25% (.25)
                       South Alabama Bank     -         10% (.10)
                       SouthTrust Bank        -        4.5% (.045)
                       Commonwealth Bank      -         .5% (.005)
</TABLE>

         Section 1.29. "Person" means an individual, partnership, corporation,
business trust, joint stock company, trust, unincorporated association, joint
venture, governmental authority, or other entity of whatever nature.

         Section 1.30. "Regions Bank" shall mean Regions Bank, an Alabama
banking corporation.

         Section 1.31. "Request for Advance" shall have the meaning assigned to
such term in Section 2.02(a).

         Section 1.32. "South Alabama Bank" shall mean South Alabama Bank, an
Alabama banking corporation.

         Section 1.33. "SouthTrust Bank" shall mean SouthTrust Bank, N.A., a
national banking association.

         Section 1.34. "Subsidiary" shall mean a corporation, general
partnership, limited liability company, limited partnership or other business
entity of which the shares, partnership or membership interests having ordinary
voting power to elect a majority of the board of directors, general partners,
managing partners or managers of such business entity are at the time owned, or
the management of which is otherwise controlled, directly or indirectly, through
one or more intermediaries, or both, by Borrower.

         Section 1.35. "Taxes" shall have the meaning assigned to such term in
Section 3.07.

         Section 1.36. "Total Commitment" shall mean $20,000,000.00.

         Section 1.37. "Whitney Bank" shall mean Whitney National Bank, a
national banking association.

         Section 1.38. Other Definitional Provisions.

         (a) All terms defined in this Agreement shall have the above defined
meanings when used in the Note or any Loan Documents, certificate, report or
other document made or delivered pursuant to this Loan Agreement, unless the
context thereof shall otherwise require.

         (b) Defined terms used herein in the singular shall import the plural
and vice-versa.


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         (c) The words "hereof", "herein", "hereunder" and similar terms when
used in this Agreement shall refer to this Agreement as a whole and not to any
particular provision of this Agreement.

                                   ARTICLE II
                               THE REVOLVING LOANS

         Section 2.01. Revolving Commitments. Subject to the terms and
conditions of the Agreement, each Lender severally (and not jointly) agrees to
lend to Borrower on a revolving, basis, in one or more Advances, from time to
time during the Commitment Period, an amount equal to such Lender's Percentage
of amounts requested by Borrower in each Request for Advance; provided, however,
that (a) total Loans outstanding at any one time shall not exceed $20,000,000,
(b) no Lender shall be obligated to make an advance if such advance would cause
the Lender's Percentage of the unpaid principal balance of the indebtedness
evidenced by the Note to be in excess of such Lender's Committed Sum, (c) each
advance shall be in an amount not less than $100,000.00, and (d) each advance
shall be made ratably by all Lenders in accordance with their respective
Percentages. Within the limits of this Section 2.01, during the Commitment
Period Borrower may borrow, repay and reborrow in accordance with the terms and
conditions of this Agreement.

         Section 2.02. Advances.

         (a) Request for Advance. Borrower shall give Agent telephonic notice by
noon, local time in Mobile, Alabama, on the day of each requested Borrowing
hereunder, confirmed in writing by hand delivery or facsimile within one (1)
hour of such telephonic notice (a "Request for Advance"), specifying the
aggregate amount of such Borrowing.

         (b) Notice Irrevocable. Each Request for Advance shall be irrevocable
and binding on Borrower, and Borrower shall indemnify each Lender against any
cost, loss or expense incurred by such Lender as a result of any failure to
fulfill, on or before the date specified for an Advance, the conditions to the
making of such Advance set forth herein, including without limitation, any cost,
loss or expense incurred by reason of the liquidation or reemployment of
deposits or other funds acquired by any Lender to fund the Advance to be made by
such Lender as part of such Borrowing.

         (c) Funding. After receiving a Request for Advance in the manner
provided herein, Agent shall promptly notify each Lender by telephone (confirmed
immediately by telecopier, telex or cable), telecopier, telex or cable of the
term's of such notice and such Lender's Percentage of such Advance. Each Lender
shall, before 2:00 p.m., local time in Mobile, Alabama, on the date


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an Advance is requested as specified in a Request for Advance, deposit with
Agent such Lender's Percentage of such Advance in immediately available funds.
Upon apparent fulfillment of all applicable conditions set forth herein and
after receipt by Agent of such funds, Agent shall deposit such funds into the
Borrowing Account. The failure of any Lender to make any Advance required to be
made by it hereunder shall not relieve any other Lender of its obligation to
make its Advance hereunder. If any Lender fails to provide its Percentage of any
Advance and if all conditions to such Advance have apparently been satisfied,
Agent will make available to Borrower the funds received by it from the other
Lenders. Neither Agent nor any Lender shall be responsible for the performance
by any other Lender of its obligations hereunder. In the event of any failure by
a Lender to make an Advance required hereunder, the other Lenders may (but shall
not be required to) purchase (on a pro rata basis, according to their respective
Percentages) such Lender's interest in, the Note.

         Unless Agent shall have received notice from a Lender prior to 2:00
p.m., local time in Mobile, Alabama, on the date of any Advance that such Lender
will not make available to Agent such Lender's Percentage of such Advance, Agent
may assume that such Lender has made such amount available to Agent on the date
of such Advance and Agent may, in reliance upon such assumption, make available
a corresponding amount to or on behalf of Borrower on such date. If and to the
extent any Lender shall not have so made its Percentage of any Advance available
to Agent, Borrower agrees to repay to Agent forthwith on demand such
corresponding amount together with interest thereon, for each day from the date
such amount is made available to or on behalf of Borrower until the date such
amount is repaid to Agent, at the interest rate under the Note.

         Section 2.03. Commitment Fees. Borrower agrees to pay to Agent, for the
account of each Lender, availability fees for the Commitment Period computed at
a rate per annum equal to one-eighth of one percent (1/8 of 1 %) on the average
daily unborrowed amount of such Lender's Committed Sum in effect during the
period for which payment is made. Such commitment fees shall be payable annually
in arrears on the first Business Day after the anniversary of the Note and again
at the maturity date of the Note.

         Section 2.04. Termination of Commitment by Borrower. Borrower may at
any time, upon not less than thirty (30) Business Days' prior written notice to
Lenders, terminate the Commitment provided, however, that upon the termination
of the Commitment, all amounts due under the Note and other Loan Documents shall
be immediately due and-payable.

         Section 2.05. Use of Proceeds. The proceeds of each Borrowing shall be
used for the general corporate purposes of Borrower.


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                                   ARTICLE III
                             NOTES AND NOTE-PAYMENTS

         Section 3.01. Note. The Advances shall be evidenced by a promissory
note (the "Note") executed by Borrower, which Note shall (a) be dated the date
hereof, (b) be in the principal amount of $20,000,000.00, (c) be payable to the
order of Agent, as Agent for the Lenders, at the office of Agent, (d) bear
interest in accordance herewith, and (e) be in the form of Exhibit "A" attached
hereto, with blanks appropriately completed in conformity herewith. The Agent is
authorized, but is not required, to endorse on the schedule attached to the Note
appropriate notations evidencing the date and amount of each Advance as well as
the amount of each payment made by Borrower thereunder.

         Section 3.02. Interest Rate. The Borrower shall pay interest to the
Agent for the ratable benefit of the Lender, on the outstanding and unpaid
principal amount of the Loan at the rate of LIBOR plus eighty basis points
(.80%) per annum, based on a 365-day year, or the prime rate as reported in the
Money Rates section of The Wall Street Journal, minus 125 basis points (1.25%).
The Prime - Based Rate shall be adjusted as of the date each change in the prime
rate is reported in the Money Rates section of The Wall Street journal. The
interest rate shall be adjusted on the first day of each calendar month, based
upon LIBOR in effect as of the first Business Day of such month, and shall
remain in effect throughout such calendar month.

         Section 3.03. Principal Payments and Prepayments.

         (a) Payment of the Note. The unpaid principal amount of the Note, and
all accrued but unpaid interest thereon, shall be due and payable on the earlier
of (i) the Commitment Termination Date, or (ii) the date on which the Note
becomes due and payable under the provisions of Section 7.02 hereof.

         (b) Optional Principal Prepayments on the Note. At any time and from
time to time Borrower may prepay without premium or penalty the principal of the
Note then outstanding, in whole or in part.

         Section 3.04. Payment of Interest on the Note. Interest upon the Note
shall be calculated at the end of each calendar month and shall be due and
payable on the first business day of the next calendar month and at the
Commitment Termination Date.

         Section 3.05. Manner and Application of Payments. All payments and
prepayments of principal of, and interest on, the Note shall be made by Borrower
to Agent before 2:00 p.m., local time in Mobile, Alabama, in federal or other
'immediately available funds at Agent's principal banking office in Mobile,
Alabama. Any payment or prepayment received by Agent after 2:00 p.m.,


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<PAGE>   10


local time in Mobile, Alabama, shall be deemed to have been received by Agent on
the next succeeding Business Day. Should the principal of or interest on the
Note, or any commitment fee, become due and payable on a day other than a
Business Day, the maturity thereof shall be extended to the next succeeding
Business Day. Each payment received by Agent hereunder for the account of
Lenders shall be promptly distributed by Agent to each Lender.

         Section 3.06. Pro Rata Treatment. Each payment and each prepayment
received by Agent for the account of Lenders shall be distributed to each Lender
entitled to share in such payment in accordance with the Percentage of such
Lender (or in accordance with such Lender's pro rata share of total Advances, in
the event that such Lender's pro rata share of Advances is not equal to such
Lender's Percentage).

         Section 3.07. Taxes.

         (a) Any and all payments by Borrower hereunder or under the Note shall
be made in accordance with this Article III, free and clear of and without
deduction for any and all present or future taxes, levies, imposts, deductions,
charges or withholdings, and all liabilities with respect thereto.

         (b) Borrower shall pay any-present or future stamp or documentary taxes
or any other excise or property taxes, charges or similar levies which arise
from any payment made hereunder or under the Loan Documents or from the
execution, delivery or registration of, or otherwise with respect to, any of the
Loan Documents.

         (c) Without prejudice to the survival of any other agreement of
Borrower hereunder, the agreements and obligations of Borrower contained in this
Section 3.07 shall survive the payment in full of the Obligations.

         Section 3.08. Indemnity. Borrower shall indemnify each Lender and hold
each Lender harmless from any loss or expense or loss of margin which such
Lender may sustain or incur as a consequence of Borrower's failure or refusal to
borrow after Borrower has given a Request for Advance pursuant to Section
3-02(a). This covenant shall survive termination of this Agreement and payment
of the Obligations for a period of one (1) year. A statement setting forth the
calculations of any amounts payable pursuant to this subsection submitted by a
Lender to Borrower and Agent shall be conclusive in the absence of manifest
error.


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                                   ARTICLE IV
                              CONDITIONS PRECEDENT

         Section 4.01. Initial Advance. The obligation of each Lender to make
the initial Advance hereunder is subject to the condition precedent that, on or
before the date of such Advance, Agent shall have received for each Lender the
following, each dated as of the date of such Advance, in form and substance
satisfactory to Agent and such Lender:

         (a) Note. The duly executed Note.

         (b) Resolutions of Borrower. Resolutions of Borrower approving the
Loans contemplated hereby, duly adopted by Borrower's Board of Directors and
accompanied by a certificate of the Secretary or Assistant Secretary of Borrower
stating that such resolutions are true and, correct, have not been altered or
repealed and are in full force and effect.

         (c) Mobile Gas Service Corporation. All obligations of Mobile Gas
Corporation under the Revolving Credit Agreement by and among Mobile Gas Service
Corporation and the Agent and Lenders shall concurrently be satisfied, and the
Commitment therein shall be terminated.

         Section 4.02. All Advances. The obligation of each Lender to make any
Advance under this Agreement (including the initial Advance) shall be subject to
the following conditions precedent:

         (a) No Defaults. As of the date of the making of such Advance, there
shall exist no Default or Event of Default.

         (b) Compliance with Agreement. Borrower shall have performed and
complied with all agreements and conditions contained herein and in each of the
Loan Documents which are required to be performed or complied with by Borrower
before or on the date of such Advance.

         (c) Request for Advance. Agent shall have received from Borrower a
Request for Advance in the form attached hereto as Exhibit "B", dated as of the
date of such Borrowing and signed by an authorized officer of Borrower.

         (d) Representations and Warranties. The representations and warranties
contained in Article V hereof and in each of the Loan Documents shall be true in
all respects on the date of making of such Advance, with the same force and
effect as though made on and as of that date.


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         (e) Bankruptcy Proceedings. No proceeding or case under Debtor Law
shall have been commenced by or against Borrower or any direct or indirect
Subsidiary of Borrower.

                                    ARTICLE V
                         REPRESENTATIONS AND WARRANTIES

         To induce Lenders to make the Loans hereunder, Borrower represents and
warrants Agent and to Lenders that:

         Section 5.01. Organization and Good Standing. Borrower is a corporation
duly organized and existing in good standing under the laws of the State of
Alabama, and has the corporate power and authority to own its properties and
assets and to transact the business in which it is engaged.

         Section 5.02. Authorization and Power. Borrower has the corporate power
and requisite authority to execute, deliver and perform the Loan Documents to be
executed by Borrower. Borrower is duly authorized, and has taken all corporate
action necessary to authorize Borrower, to execute, deliver and perform the Loan
Documents executed by Borrower. Borrower is and will continue to be duly
authorized to perform the Loan Documents executed by Borrower and the
Obligations.

         Section 5.03. No Conflicts or Consents. Neither the execution and
delivery of the Loan Documents, nor the on summation of any of the transactions
therein contemplated, nor compliance with the terms and provisions thereof, will
materially contravene or conflict with any provision of law, statute or
regulation to which Borrower is subject or any judgment, license, order or
permit applicable to Borrower, or any indenture, loan agreement, mortgage, deed
of trust, or other agreement or instrument to which Borrower is a party or to
which Borrower may be subject, or violate any provision of the charter or bylaws
of Borrower. No consent, approval, authorization or order of any court or
Governmental Authority or third party is required and has not been obtained in
connection with the execution and delivery by Borrower of the Loan Documents or
to consummate the transactions contemplated hereby or thereby.

         Section 5.04. Enforceable Obligations. The Loan Documents have been
duly executed and delivered by Borrower and are the legal and binding
obligations of Borrower, enforceable in accordance with their respective terms,
except as limited by Debtor Laws.

         Section 5.05. No Default. No event known to Borrower has occurred and
is continuing which constitutes a Default or an Event of Default.


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         Section 5.06. Use of Proceeds: Margin Stock. The proceeds of the Loans
will be used by Borrower solely for the purposes specified in this Agreement.
None of such proceeds will be used for the purpose of purchasing or carrying any
"margin stock" as defined in Regulation U, Regulation X, or Regulation G, or for
the purpose of reducing or retiring any indebtedness which was originally
incurred to purchase or carry a "margin stock" or for any other purpose which
might constitute this transaction a "purpose credit" within the meaning of such
Regulation U, Regulation X, or Regulation G. Borrower is not engaged in the
business of extending credit for the purpose of purchasing or carrying margin
stocks. Borrower has neither taken nor will take, and no Person acting on behalf
of Borrower has taken or will take, any action which might cause the Note or any
of the other Loan Documents, including this Agreement, to violate Regulation U,
Regulation X, or Regulation G or any other regulations of the Board of Governors
of the Federal Reserve System or to violate Section 8 of the Securities Exchange
Act of 1934 or any rule or regulation thereunder, in each case as now in effect
or as the same may hereinafter be in effect. Borrower neither owns, nor does any
subsidiary of Borrower own, "margin stock" as herein defined.

         Section 5.07. Taxes. All tax returns required to be filed by Borrower
in any jurisdiction have been filed and all taxes (including mortgage recording
taxes), assessments, fees and other governmental charges upon Borrower or upon
any of its properties, income or franchises have been- paid prior to the time
that such taxes could give rise to a lien thereon. There is no known material
proposed tax assessment against Borrower and Borrower is not aware of any basis
for such assessment.

                                   ARTICLE VI
                                    COVENANTS

         So long as Lenders have any commitment to make Advances hereunder, and
until payment in full of the Note, Borrower agrees that (unless Lenders shall
otherwise consent in writing):

         Section 6.01. Financial Information. Borrower shall deliver to each
Lender, within three (3) days of its transmittal for filing with the Securities
and Exchange Commission, a true and correct copy of each Form 10-Q and Form 10-K
of Borrower.

         Section 6.02. Additional Financial Information. Borrower shall deliver
to each Lender such additional financial information as Lenders may reasonably
request from time to time.

         Section 6.03. Payment of Taxes and Other Indebtedness. Borrower shall
pay and discharge (a) all taxes, assessments and governmental charges or levies
imposed upon it before delinquent, and (b) all other indebtedness of


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Borrower; provided, however, that Borrower shall not be required to pay any such
tax, assessment, charge or levy if and so long as the amount, applicability or
validity thereof shall be contested in good faith by appropriate proceedings,
and appropriate accruals therefore shall have been established in accordance
with generally accepted accounting principles.

         Section 6.04. Maintenance of Existence and Rights; Conduct of Business.
Borrower shall preserve and maintain its corporate existence and all of its
rights, privileges and franchises necessary or desirable in the normal conduct
of its business, and conduct its business in an orderly and efficient manner
consistent with good business practices.

         Section 6.05. Compliance with Material Agreements. Borrower shall
comply in all material respects with all material agreements, indentures,
mortgages or documents binding on it or affecting its properties or business.

         Section 6.06. Minimum Stockholders' Equity Plus Minority Interest.
Borrower, and its consolidated subsidiaries, shall at all times maintain a Total
Stockholders' Equity, plus Minority Interest, on a consolidated basis of not
less than Fifty-Five Million and No/100 Dollars ($55,000,000.00).

         Section 6.07. Leverage Ratio. Borrower, and its consolidated
subsidiaries, will maintain at all times, on a consolidated basis, a ratio of
Total Liabilities plus Long-Term Debt, (excluding short-term debt used to
purchase temporary investments) to Stockholders Equity plus Minority Interest of
not greater than 2.0 to 1.0.

         Section 6.08. Debt/Earnings Ratio. Borrower, and its consolidated
subsidiaries, will maintain at all times, on a consolidated basis, a ratio of
funded debt (excluding short-term debt used to purchase temporary investments)
to EBITDA (after dividends) of not more than 4.5 to 1. "'EBITDA" means earnings
before interest, taxes, depreciation, and amortization. Funded debt is defined
as the sum of Long-Term Debt, Current Maturities of Long-Term Debt, and Notes
Payable to Banks.

         Section 6.09. Mobile Gas Service Corporation. (a) Borrower shall not
convey, sell, assign, transfer or otherwise dispose of any interest in Mobile
Gas Service Corporation or its capital stock, and (b) Borrower shall not allow
the gross assets of Mobile Gas Service Corporation to be less than $115,000,000
at any time during the term of the Loans; provided, however, that should Mobile
Gas Service Corporation dividend its subsidiary MGS Storage Services, Inc. to
Borrower so that MGS Storage Services, Inc. becomes a direct subsidiary of
Borrower, then the $115,000,000 requirement of this subsection shall be reduced
by a dollar amount equal to the value allocated to MGS Storage Services, Inc. on
the balance sheet of Mobile Gas Service Corporation for the month ended closest
to the date of such dividend.


                                       14
<PAGE>   15


         Section 6.10. Annual Payoff. Beginning in the year 2000 for 45
consecutive days during each calendar year that the Loan(s) is Outstanding the
Borrower will reduce the balance outstanding on the Loan(s) to zero.

         Section 6.11. Due on Sale Provision. Upon any sale, lease, transfer or
disposition of either a controlling interest in Borrower, or a majority of its
now owned or hereafter acquired assets, or consolidation or merger into another
entity, this Loan(s) and the Note shall immediately become due and payable in
full.

                                   ARTICLE VII
                                EVENTS OF DEFAULT

         Section 7.01. Events of Default. An "Event of Default" shall exist if
any one or more of the following events (herein collectively called "Events of
Default") shall occur and be continuing:

         (a) Borrower shall fail to pay within five (5) days of when due any
principal of, or interest on, any Note or any fee, expense or other payment
required hereunder;

         (b) any representation or warranty made under this Agreement, or in any
certificate or financial statement furnished or made to Lenders pursuant hereto
or in connection herewith or with the Loans hereunder, shall prove to be untrue
or inaccurate in any material respect as of the date on which such
representation or warranty is made;

         (c) default shall occur in the performance of any of the covenants or
agreements of Borrower contained herein, and such default remains uncured ten
(10) days after notice of such default is given to Borrower;

         (d) default shall occur in the payment of any material Indebtedness of
Borrower (other than the Obligations) or default on the part of Borrower shall
occur in respect of any note, loan agreement or credit agreement relating to any
such indebtedness and such default shall continue for more than the period of
grace, if any, specified therein; or any such Indebtedness shall become due
before its stated maturity by acceleration of the maturity and shall not be
promptly paid or extended, thereof or shall become due by its terms and shall
not be promptly paid or extended;

         (e) Borrower shall (i) apply for or consent to the appointment of a
receiver, trustee, custodian, intervenor or liquidator of itself or of all or a
substantial part of Borrower's assets, (ii) file a voluntary petition in
bankruptcy, admit in a writing delivered or furnished to a third party
(including the Agent or Lenders) that such Borrower is unable to pay its debts


                                       15
<PAGE>   16


as they become due or generally not pay its debts as they become due (iii) make
a general assignment for the benefit of creditors, (iv) file a petition or
answer seeking reorganization or an arrangement with creditors or to take
advantage of any bankruptcy or insolvency laws or other Debtor Law, (v) file an
answer admitting the material allegations of, or consent to, or default in
answering, a petition filed against Borrower in any bankruptcy, reorganization
or insolvency proceeding, or (vi) take corporate action for the purpose of
effecting any of the foregoing;

         (f) an involuntary petition or complaint shall be filed against
Borrower seeking bankruptcy or reorganization of Borrower or the appointment of
a receiver, custodian, trustee, intervenor or liquidator of Borrower, or all or
substantially all of the assets of Borrower, and such petition or complaint
shall not have been dismissed within ninety (90) days of the filing thereof; or
an order, order for relief, judgment or decree shall be entered by any court of
competent jurisdiction or other competent authority approving a petition or
complaint seeking reorganization of Borrower or appointing a receiver,
custodian, trustee, intervenor or liquidator of Borrower, or of all or
substantially all of the assets of Borrower.

         Section 7.02. Remedies Upon Event of Default. If an Event of Default
shall have occurred and be continuing, then Agent shall, at the request of
Lenders, and may, with the consent of Lenders, exercise any one or more of the
following rights and remedies, and any other remedies provided in any of the
Loan Documents, as Lenders in their sole discretion may deem necessary or
appropriate: (a) terminate Lenders' commitment to lend hereunder, (b) declare
the principal of, and all interest then accrued on, the Note and any other
liabilities hereunder to be forthwith due and payable, whereupon the same shall
forthwith become due and payable without presentment, demand, protest, notice of
default, notice of acceleration or of intention to accelerate or other notice of
any kind, all of which Borrower hereby expressly waives, anything contained
herein or in the Note to the contrary notwithstanding, (c) reduce any claim to
judgment, and/or (d) without notice of Event of Default or demand, pursue and
enforce any of Agent's or Lenders' rights and remedies under the Loan Documents,
or otherwise provided under or pursuant to any applicable law; provided,
however, that if any Event of Default specified in Section 7.01 (f) shall occur
with respect to Borrower, the principal of, and all interest on, the Notes and
other liabilities hereunder shall thereupon become due and payable concurrently
therewith, and Lenders' obligations to lend shall immediately terminate
hereunder, without any further action by Agent or any Lender and without
presentment, demand, protest, notice of default, notice of acceleration or of
intention to accelerate or other notice of any kind, all of which Borrower
hereby expressly waives.


                                       16
<PAGE>   17


                                  ARTICLE VIII
                            THE AGENT; PARTICIPATIONS

         Section 8.01. Appointment and Authorization. Each Lender hereby
irrevocably appoints and authorizes Agent to take such action on its behalf and
to exercise such powers under the Loan Documents as are delegated to Agent by
the terms hereof and thereof, together with such powers as are reasonably
incidental thereto. With respect to its Commitment and the Advances made by it,
AmSouth Bank shall have the same rights and powers under this Agreement as any
other Lender and may exercise the same as though it were not Agent; and the term
"Lender" or "Lenders" shall, unless otherwise expressly indicated, include
AmSouth Bank in its capacity as a Lender. Agent may accept deposits from, lend
money to, act as trustee under indentures of, and generally engage in any kind
of business with, Borrower, any of Borrower's Affiliates and any Person which
may do business with Borrower or any of Borrower's Affiliates, all as if Agent
were not Agent hereunder and without any duty to account therefor to Lenders.

         Section 8.02. Agent's Fees. Borrower shall pay to Agent for its own
account fees, if any, in the amounts and at the times agreed between them.

         Section 8.03. Documents. Agent shall not be under a duty to examine or
pass upon the validity, effectiveness, enforceability, genuineness or value of
any of the Loan Documents or any other instrument or document furnished pursuant
thereto or in connection therewith, and Agent shall be entitled to assume that
the same are valid, effective, enforceable and genuine and what they purport to
be.

         Section 8.04. Resignation or Removal of Agent. Subject to the
appointment and acceptance of a successor Agent as provided below, the Agent may
resign at any time by giving fifteen (15) Business Days' written notice thereof
to Lenders and Borrower. Upon any such resignation, Borrower shall have the
right to appoint a successor Agent from among the remaining Lenders. If no
successor Agent shall have been so appointed by Borrower and shall have accepted
such appointment within fifteen (15) Business Days after the retiring Agent's
giving of notice of resignation, then the retiring Agent may, on behalf of the
Borrower, appoint a successor Agent. Upon the acceptance of any appointment as
Agent hereunder by a successor Agent, such successor Agent shall thereupon
succeed to and become vested with all the rights, powers, privileges and duties
of the retiring Agent, and the retiring Agent shall be discharged from its
duties and obligations hereunder. After any retiring Agent's resignation
hereunder as Agent, the provisions of this Article VIII shall continue in effect
for its benefit in respect to any actions taken or omitted to be taken by it
while it was acting as Agent.


                                       17
<PAGE>   18


         Section 8.05. Responsibility of Agent. It is expressly understood and
agreed that the obligations of Agent under the Loan Documents are only those
expressly set forth in the Loan Documents and that Agent shall be entitled to
assume that no Default or Event of Default has occurred and is continuing,
unless Agent has actual knowledge of such fact or has received notice from a
Lender that such Lender considers that a Default or an Event of Default has
occurred and is continuing and specifying the nature thereof. Lenders recognize
and agree that Agent shall not be required to determine independently whether
the conditions described in Article IV have been satisfied and, in disbursing
funds to Borrower, may rely fully upon statements contained in the relevant
Request for Advance . Neither Agent nor any of its directors, officers or
employees shall be liable for any action taken or omitted to be taken by it
under or in connection with Loan Documents, except for its own gross negligence
or willful misconduct. Agent shall incur no liability under or in respect of any
of the Loan Documents by acting upon any notice, consent, certificate, warranty
or other paper or instrument believed by it to be genuine or authentic or to be
signed by the proper party or parties, or with respect to anything which it may
do or refrain from doing in the reasonable exercise of its judgment, or which
may seem to it to be necessary or desirable in the circumstances.

         Agent shall not be responsible to Lenders for any recitals, statements,
representations or warranties contained in this Agreement, or in any certificate
or other document referred to or provided for in, or received by any Lender
under, this Agreement, or for the value, validity, effectiveness, genuineness,
enforceability or sufficiency of this Agreement or any document referred to or
provided for herein or for any failure by Borrower to perform any of its
obligations hereunder. Agent may, after consultation with Lenders, employ agents
and attorneys-in-fact and shall not be answerable, except as to money or
securities received by it or its authorized agents, for the negligence or
misconduct of any such agents or attorneys-in-fact selected by it with
reasonable care.

         The relationship between Agent and each of the Lenders is only that of
agent and principal and has no fiduciary aspects, and Agent's duties hereunder
are acknowledged to be only ministerial and not involving the exercise of
discretion on its part. Nothing in this Agreement or elsewhere contained shall
be construed to impose on Agent any duties or responsibilities other than those
for which express provision is herein made. In performing its duties and
functions hereunder, Agent does not assume and shall not be deemed to have
assumed, and hereby expressly disclaims, any obligation or responsibility toward
or any relationship of agency or trust with or for Borrower. As to any matters
not expressly provided for by this Agreement (including, without limitation,
enforcement or collection of the Note), Agent shall not be required to exercise
any discretion or take any action, but shall be required to act or to refrain
from acting (and shall be fully


                                       18
<PAGE>   19


protected in acting or refraining from acting) upon the instructions of Lenders
and such instructions shall be binding upon all Lenders; provided, however, that
Agent shall not be required to take any action which exposes Agent to personal
liability or which is contrary to this Agreement or applicable law.

         Section 8.06. Notices of Event of Default. In the event that Agent
shall have acquired actual knowledge of any Event of Default or of an event
which, with the giving of notice or the lapse of time, or both, would constitute
an Event of Default, Agent shall promptly give notice thereof to the other
Lenders. In the event that any Lender shall have acquired actual knowledge of
any Event of Default or of any event which, with the giving of notice or the
lapse of time, or both, would constitute an Event of Default, such Lender shall
promptly give notice thereof to the Agent and other Lenders.

         Section 8.07. Sale or Assignment. Each participation shall constitute
an assignment, without recourse to AmSouth Bank, of any undivided interest in
the Loans, the Loan Documents, and any and all property of Borrower or proceeds
thereof that may be received in payment from the Borrower or applied to the
Loans. Nothing in this Agreement nor in any other agreement among Lenders and
Agent shall be construed to create a loan by any Lender to Agent or any other
Lender unless expressly set forth therein.

         Section 8.08. Catch-All. Except for Loan repayments described herein,
no Lender shall have any interest in other payments received by the Agent from
Borrower.

         Section 8.09. Corporate Power. Each Lender and the Agent represents and
warrants to all other Lenders and Agent that the making and performance of this
Agreement is within its power and has been duly authorized by all necessary
corporate and other action by it, that this Agreement is in compliance with all
applicable laws and regulations promulgated thereunder, and does not conflict
with any agreements by which it is bound, and that this Agreement has been duly
executed by it, and constitutes the legal, valid and binding obligation of it,
enforceable in accordance with its respective terms.

         Section 8.10. Credit Analysis. Each Lender has conducted and will
conduct its own credit analysis, without reliance on Agent, and based upon such
documents and information as it has deemed appropriate, made and will make its
decisions called for hereunder, and will continue to be responsible for making
its own independent appraisal of the credit, financial condition, and all other
matters concerning Borrower. Each Lender represents and warrants that its
participation in the Loan and Loan Documents is an ordinary commercial lending
transaction and not a "sale" of a "security" under any federal or state
securities law, rule or regulation.


                                       19
<PAGE>   20


         Section 8.11. Administration of Loan. Only upon the unanimous consent
of each Lender may the Agent (i) agree to any modification of any of the terms
of the Credit Documents or any other agreement or instrument evidencing or
securing this Loan; (ii) waive any of such terms or give or withhold consents or
approvals to any actions or failure to act by the Borrower; (iii) reduce the
principal of or the interest rate or extend the stated maturity of the Loan;
(iv) agree upon any extension, modification, refinancing, refunding, assumption
or other restructuring of the Loan.

                                   ARTICLE IX
                                  MISCELLANEOUS

         Section 9.01. Accounting Terms. All accounting terms not specifically
defined in this Agreement shall be construed in accordance with generally
accepted accounting principles.

         Section 9.02. Waiver. No failure to exercise, and no delay in
exercising, on the part of any Lender, any right hereunder shall operate as a
waiver thereof, nor shall any single or partial exercise thereof preclude any
other or further exercise thereof or the exercise of any other right. The rights
of Lenders hereunder and under the Loan Documents shall be in addition to all
other rights provided by law. No modification or waiver of any provision of this
Agreement, the Notes or any Loan Documents, nor consent to departure therefrom,
shall be effective unless in writing and no such consent or waiver shall extend
beyond the particular case and purpose involved. No notice or demand given in
any case shall constitute a waiver of the right to take other action in the
same, similar or other instances without such notice or demand.

         Section 9.03. Payment of Expenses. Borrower agrees, in the event that
Lenders prevail, to pay all reasonable costs and expenses of Lenders (including,
without limitation, the reasonable attorneys' fees of Lenders' legal counsel)
incurred by Lenders in connection with the preservation and enforcement of
Agent's and Lenders' rights under this Agreement and/or the Notes.

         Section 9.04. Notices. Except for telephonic notices permitted herein,
any notices or other communications required or permitted to be given by this
Agreement or any other documents and instruments referred to herein must be (a)
given in writing and personally delivered or mailed by prepaid United States
mail, or (b) made by courier, overnight delivery service or telecopier or telex
delivered or transmitted, to the party to whom such notice of communication is
directed, to the address of such party as follows:


                                       20
<PAGE>   21


         (a)      Borrower:   EnergySouth, Inc.
                              Post Office Box 2607
                              Mobile, Alabama 36652

                              Attention: John S. Davis

                              Telecopier No.: (334) 476-1745


         (b)      Agent:      AmSouth Bank, N.A.
                              Post Office Drawer 1628
                              Mobile, Alabama 36633-1628

                              Attention: Robert F. Diehl, Jr.

                              Telecopier No.: (334) 438-8377


         (b)      Lenders:    AmSouth Bank, N.A.
                              Post Office Drawer 1628
                              Mobile, Alabama 36633-1625

                              Attention: Robert F. Diehl, Jr.

                              Telecopier No.: (334) 438-8377


                              Regions Bank
                              Post Office Drawer 2527
                              Mobile, Alabama 36622

                              Attention: Scott Patterson

                              Telecopier No.: (334) 690-1020


                              Whitney National Bank
                              Post Office Box 9789
                              Mobile, Alabama 36691

                              Attention: Kyle Pugh

                              Telecopier No.: (334) 665-1675


                                       21
<PAGE>   22



                              South Alabama Bank
                              Post Office Box 3067
                              Mobile, Alabama 36652

                              Attention: Robbie Murray

                              Telecopier No.: (334) 433-5065


                              SouthTrust Bank, N.A.
                              Post Office Box 1508
                              Mobile, Alabama 36633

                              Attention: Sharon Johnson

                              Telecopier No.: (334) 431-9256


                              Commonwealth National Bank
                              Post Office Box B
                              Mobile, Alabama 36601

                              Attention: Ernestine Moore

                              Telecopier No.: (334) 476-5946

Any such notice or other communication shall be deemed to have been given on the
day it is received, provided, however, that any telephonic or other notice
received by Agent after 12:00 noon local time in Mobile, Alabama, on any day
from Borrower pursuant to Section 2.02(a) (with respect to a Request for
Advance) shall be deemed for the purposes of such Section to have been given by
Borrower on the next succeeding Business Day. Any party may change its address
for purposes of this Agreement by giving notice of such change to the other
parties pursuant to this Section 9.04.

         Section 9.05. Governing Law. This Agreement shall be governed by and
construed in accordance with the laws of the United States of America and the
State of Alabama.

         Section 9.06. Confidentiality. Agent and each Lender agree to hold any
confidential information which they may receive from Borrower pursuant to this
Agreement in confidence, except for disclosure (a) to other Lenders, (b) to
legal counsel, accountants, and other professional advisors, (c) to regulatory
officials as required by law, rule or regulation, (d) as required by law or
legal process or in connection with any legal proceeding, or (e) as otherwise
permitted by the Loan Documents.


                                       22
<PAGE>   23


         Section 9.07. Nonliability of Lenders. The relationship between
Borrower and Lenders is, and shall at all times remain, solely that of borrower
and lenders, and Lenders and Agent neither undertake nor assume any
responsibility or duty to Borrower to review/ inspect, supervise, pass judgment
upon, or inform Borrower of any matter in connection with any phase of
Borrower's businesses, operations, or condition, financial or otherwise. There
is not and shall not be deemed to be a fiduciary relationship between Lenders
and Borrower. Borrower shall rely entirely upon its own judgment with respect to
such matters, and any review, inspection, supervision, exercise of judgment, or
information supplied to Borrower by any Lender or Agent in connection with any
such matter is for the protection of Lenders and Agent, and neither Borrower nor
any third party is entitled to rely thereon.

         Section 9.08. No Joint Venture. Nothing herein contained or contained
in the other Loan Documents shall be deemed to create a partnership or joint
venture between Lenders and/or Agent on the one hand, and Borrower on the other
hand.

         Section 9.09. Binding Effect. The Loan Documents shall be binding upon
and inure to the benefit of Borrower, Agent and Lenders and their respective
successors, assigns and legal representatives; provided, however, that (a)
Borrower may not, without the prior written consent of Lenders, assign any
rights, powers, duties or obligations thereunder, and (b) no Lender may, without
the prior written consent of the other Lenders and Borrower, assign any rights,
powers, duties or obligations thereunder.

         Section 9.10. Entirety. The Loan Documents embody the entire agreement
between the parties and supersede all prior or contemporaneous agreements and
understandings, if any, relating to the subject matter hereof and thereof.

         Section 9.11. Headings. Section headings are for convenience of
reference only and shall in no way affect the interpretation of this Agreement.

         Section 9.12. No Third Party Beneficiary. The parties do not intend the
benefits of this Agreement to inure to any third party, nor shall this Agreement
be construed to make or render Agent or Lenders liable to any materialman,
supplier, contractor, subcontractor, purchaser or lessee of any property owned
by Borrower, or for debts or claims accruing to any such persons against
Borrower. Notwithstanding anything contained herein or in the Notes, or in any
other Loan Document, or any conduct or course of conduct by any or all of the
parties hereto, before or after signing, neither this Agreement nor any other
Loan Document shall be construed as creating any right, claim or cause of action
against Agent or Lenders, or any of their


                                       23
<PAGE>   24


officers, directors, agents or employees, in favor of any materialman, supplier,
contractor, subcontractor, purchaser or lessee of any property owned by
Borrower, nor to any other person or entity other than Borrower.

         Section 9.13. Multiple Counterparts. This Agreement may be executed in
any number of counterparts, all of which taken together shall constitute one and
the same agreement, and any of the parties hereto may execute this Agreement by
signing any such counterpart.

         IN WITNESS WHEREOF, the undersigned have executed this Agreement as of
the day and year, first above written.

                                            BORROWER

                                            ENERGYSOUTH, INC.

                                            By:  /s/ John S. Davis

                                            John S. Davis, President and Chief
                                            Executive Officer

                                            By:  /s/ Charles P. Huffman

                                            Vice President, Chief Financial
                                            Officer and Treasurer


                                            AGENT

                                            AmSOUTH BANK, N.A., as Agent for
                                            Lenders pursuant to the terms hereof

                                            By: /s/ Robert F. Diehl, Jr.

                                            Title:  Vice President


                                            LENDERS

                                            AmSOUTH BANK, N.A.

                                            By:  /s/ Robert F. Diehl Jr.

                                            Title:   Vice President


                                       24
<PAGE>   25


                                            REGIONS BANK

                                            By:  /s/ Scott S. Patterson

                                            Title:  Commercial Loan Officer


                                            WHITNEY NATIONAL BANK

                                            By: /s/ John M. Turner, Jr.

                                            Title:  State President


                                            SOUTH ALABAMA BANK

                                            By:  /s/ Robert S. Murray

                                            Title:  Vice Pres.


                                            SOUTHTRUST BANK OF ALABAMA, N.A.

                                            By:  /s/ Sharon Johnson

                                            Title:  Vice President


                                            COMMONWEALTH NATIONAL BANK

                                            By:  /s/ Earnestine Moore

                                            Title:  Senior Vice Pres.


                                       25
<PAGE>   26


                                   EXHIBIT "A"

                              REVOLVING CREDIT NOTE

$20,000,000.00                                                September 30, 1999


         FOR VALUE RECEIVED, the undersigned (the "Maker"), hereby
unconditionally promises to pay to the order of AmSOUTH BANK, N.A., a national
banking association, As Agent for the Lenders, ("the Agent")(the "Payee"), at
the offices of AmSouth Bank, N.A., as Agent (the "Agent"), at Mobile, Alabama,
or such other address given to Maker by Agent, the principal sum of TWENTY
MILLION and NO/100ths DOLLARS ($20,000,000.00), or so much thereof as may be
advanced hereunder and not repaid, together with interest on the unpaid
principal balance from day-to-day remaining, computed from the date of advance
until maturity at the rate and subject to the terms set forth below.

         This Note has been executed and delivered pursuant to the terms of that
certain Revolving Credit Agreement (the "Revolving Credit Agreement"), between
Maker, Agent and AmSouth Bank, N.A., Regions Bank, Whitney National Bank, South
Alabama Bank, SouthTrust Bank, N.A., and Commonwealth National Bank, as Lenders,
dated of even date herewith, and the "Note" referred to therein. Each
capitalized term used herein shall, unless otherwise indicated, have the meaning
assigned to such term in the Revolving Credit Agreement.

         Principal Payments and Prepayments.

         (a) Payment of the Note. The unpaid principal amount of the Note, and
all accrued but unpaid interest thereon, shall be due and payable on the earlier
of'(i) the Commitment Termination Date, or (ii) the date on which the Note
becomes due and payable under the provisions of Section 7.02 of the Revolving
Credit Agreement.

         (b) Optional Principal Prepayments on the Note. At any time and from
time to time Borrower may prepay without premium or penalty the principal of the
Note then outstanding, in whole or in part.

         Payment of Interest on the Note. Interest upon the Note shall be
calculated at the end of each calendar month and shall be due and payable on the
first business day of the next calendar month and at the Commitment Termination
Date.


<PAGE>   27


         Manner and Application of Payments. All payments and prepayments of
principal of, and interest on, the Note shall be made by Borrower to Agent
before 2:00 p.m., local time in Mobile, Alabama, in federal or other immediately
available funds at Agent's principal banking office in Mobile, Alabama. Any
payment or prepayment received by Agent after 2:00 p.m., local time in Mobile,
Alabama, shall be deemed to have been received by Agent on the next succeeding
Business Day. Should the principal of or interest on the Note, or any commitment
fee, become due and payable on a day other than a Business Day, the maturity
thereof shall be extended to the next succeeding Business Day. Each payment
received by Agent hereunder for the account of Lenders shall be promptly
distributed by Agent to each Lender.

         The Maker hereby waives demand, presentment, protest, notice of
protest, notice of dishonor, and all of the requirements necessary to hold it
liable for any of the Obligations (meaning thereby this Note and any and all
renewals and extensions thereof and any amounts due under the Revolving Credit
Agreement).

         Neither any failure nor any delay on the part of Payee in exercising
any right, power or privilege under this Note shall operate as a waiver thereof,
nor shall a single or partial exercise thereof preclude any other or further
exercise or the exercise of any other right, power or privilege. No
modification, amendment, or waiver of any provision of this Note shall be
effective unless in writing and signed by a duly authorized officer of Payee,
and then the same shall be effective only in the specific instance and for the
purpose for which given.

         This Note shall be governed and construed in accordance with the laws
of the State of Alabama.

         IN WITNESS WHEREOF, EnergySouth, Inc. has caused this instrument to be
executed by its officer thereunto, duly authorized as of the day and date first
above written.


                                       ENERGYSOUTH, INC.

                                       By: /s/ John S. Davis
                                       Title:  President and Chief Executive
                                               Officer



                                       By: /s/ Charles P. Huffman
                                       Title:  Vice President, Chief Financial
                                       Officer and Treasurer