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                                  UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                                    FORM 10-K

[X]      ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES
         EXCHANGE ACT OF 1934 FOR THE YEAR ENDED SEPTEMBER 30, 2000

[ ]      TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES
         EXCHANGE ACT OF 1934 FOR THE TRANSITION PERIOD FROM     TO
                                                             ---    ---

COMMISSION                                                         IRS EMPLOYER
   FILE                                       STATE OF            IDENTIFICATION
  NUMBER     REGISTRANT                    INCORPORATION              NUMBER
--------------------------------------------------------------------------------

1-7810       ENERGEN CORPORATION              ALABAMA               63-0757759
2-38960      ALABAMA GAS CORPORATION          ALABAMA               63-0022000

                   605 RICHARD ARRINGTON, JR. BOULEVARD NORTH
                         BIRMINGHAM, ALABAMA 35203-2707
                                 (205) 326-2700
                             HTTP://WWW.ENERGEN.COM

           Securities Registered Pursuant to Section 12(b) of the Act:
TITLE OF EACH CLASS                                 EXCHANGE ON WHICH REGISTERED
-------------------                                 ----------------------------
Energen Corporation Common Stock, $0.01 par         New York Stock Exchange
  value
Energen Corporation Preferred Stock Purchase        New York Stock Exchange
  Rights

        Securities Registered Pursuant to Section 12(g) of the Act: NONE

Indicate by a check mark whether registrants (1) have filed all reports required
to be filed by Section 13 or 15(d) of the Securities and Exchange Act of 1934
during the preceding 12 months (or for such shorter period that the registrants
were required to file such reports) and (2) have been subject to such filing
requirements for the past 90 days. YES [X] NO [ ]

Indicate by a check mark if disclosure of delinquent filers pursuant to Item 405
of Regulation S-K (Section 229.405 of this chapter) is not contained herein and
will not be contained, to the best of registrant's knowledge, in definitive
proxy or information statements incorporated by reference in Part III of this
Form 10-K or any amendment to this Form 10-K. (X)

Aggregate market value of the voting stock held by non-affiliates of the
registrants as of December 8, 2000:

               Energen Corporation                        $869,966,670

Indicate number of shares outstanding of each of the registrant's classes of
common stock as of December 8, 2000:
               Energen Corporation                   30,634,527 shares
               Alabama Gas Corporation                1,972,052 shares

Alabama Gas Corporation meets the conditions set forth in General Instruction
I(1) (a) and (b) of Form 10-K and is therefore filing this form with the reduced
disclosure format pursuant to General Instruction I(2).

                       DOCUMENTS INCORPORATED BY REFERENCE
- Energen Corporation Proxy Statement to be filed on or about December 18, 2000
  (Part III, Item 10-13)
- Portions of Energen Corporation Fiscal Year 2000 Annual Report to Shareholders
  are incorporated by reference into Part II, Items 5, 6, 7, and 8 of this
  report


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                               ENERGEN CORPORATION
                          2000 FORM 10-K ANNUAL REPORT


                                TABLE OF CONTENTS

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                                               PART I

Item 1.       Business...............................................................................3

Item 2.       Properties.............................................................................9

Item 3.       Legal Proceedings......................................................................9

Item 4.       Submission of Matters to a Vote of Security Holders....................................9


                                              PART II

Item 5.       Market for Registrant's Common Stock and Related Stockholder Matters..................12

Item 6.       Selected Financial Data...............................................................12

Item 7.       Management's Discussion and Analysis of Results of Operations
              and Financial Condition...............................................................12

Item 7a.      Quantitative and Qualitative Disclosures about Market Risk............................12

Item 8.       Financial Statements and Supplementary Data...........................................13

Item 9.       Changes in and Disagreements with Accountants on Accounting
              and Financial Disclosure..............................................................13


                                             PART III

Item 10.      Directors and Executive Officers of the Registrants...................................14

Item 11.      Executive Compensation................................................................14

Item 12.      Security Ownership of Certain Beneficial Owners and Management........................14

Item 13.      Certain Relationships and Related Transactions........................................14


                                             PART IV

Item 14.      Exhibits, Financial Statement Schedules, and Reports on Form 8-K......................15
</TABLE>


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 This Form 10-K is filed on behalf of Energen Corporation (Energen or the
                Company) and Alabama Gas Corporation (Alagasco).

FORWARD-LOOKING STATEMENT AND RISK: Certain statements in this report, express
expectations of future plans, objectives and performance of the Company and its
subsidiaries, and constitute forward-looking statements made pursuant to the
Safe Harbor provision of the Private Securities Litigation Reform Act of 1995.
Except as otherwise disclosed, the Company's forward-looking statements do not
reflect the impact of possible or pending acquisitions, divestitures or
restructurings. We undertake no obligation to correct or update any
forward-looking statements, whether as a result of new information, future
events or otherwise. All statements based on future expectations rather than on
historical facts are forward-looking statements that are dependent on certain
events, risks and uncertainties that could cause actual results to differ
materially from those anticipated. Some of these include, but are not limited
to, economic and competitive conditions, inflation rates, legislative and
regulatory changes, financial market conditions, future business decisions, and
other uncertainties, all of which are difficult to predict. There are numerous
uncertainties inherent in estimating quantities of proved oil and gas reserves
and in projecting future rates of production and timing of development
expenditures. The total amount or timing of actual future production may vary
significantly from reserves and production estimates. In the event Energen
Resources, the Company's oil and gas subsidiary, is unable to fully invest its
planned acquisition, development and exploratory expenditures, future operating
revenues, production, and proved reserves could be negatively affected. The
drilling of development and exploratory wells can involve significant risks,
including those related to timing, success rates and cost overruns and these
risks can be affected by lease and rig availability, complex geology and other
factors. Although Energen Resources makes use of futures, swaps and fixed-price
contracts to mitigate risk, fluctuations in future oil and gas prices could
affect materially the Company's financial position and results of operation;
furthermore, such risk mitigation activities may cause the Company's financial
position and results of operations to be materially different from results that
would have been obtained had such risk mitigation activities not occurred. In
addition, the Company cannot guarantee the absence of errors in input data,
calculations and formulas used in its estimates, assumptions and forecasts.

PART I

ITEM 1. BUSINESS

GENERAL

Energen Corporation is a Birmingham-based diversified energy holding company
engaged primarily in the purchase, distribution, and sale of natural gas,
principally in central and north Alabama, and in the acquisition, development,
exploration and production of oil, natural gas and natural gas liquids in the
continental United States. Its two major subsidiaries are Alabama Gas
Corporation (Alagasco) and Energen Resources Corporation.

Energen was incorporated in Alabama in 1978 in connection with the
reorganization of its oldest subsidiary, Alagasco. Alagasco was formed in 1948
by the merger of Alabama Gas Company into Birmingham Gas Company, the
predecessors of which had been in existence since the mid-1800s. Alagasco became
a public company in 1953. Energen Resources was formed in 1971 as a subsidiary
of Alagasco and became a subsidiary of Energen in the 1978 reorganization.

FINANCIAL INFORMATION ABOUT INDUSTRY SEGMENTS

The information required by this item is incorporated by reference from Note 17,
Industry Segment Information, to the Consolidated Financial Statements of the
Fiscal Year 2000 Annual Report to Shareholders and is attached herein as Part
IV, Item 14, Exhibit 13.


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NARRATIVE DESCRIPTION OF BUSINESS

-        NATURAL GAS DISTRIBUTION

         GENERAL: Alagasco is the largest natural gas distribution utility in
         the state of Alabama. Alagasco purchases natural gas through interstate
         and intrastate marketers and suppliers and distributes the purchased
         gas through its distribution facilities for sale to residential,
         commercial and industrial customers and other end-users of natural gas.
         Alagasco also provides transportation services to industrial and
         commercial customers located on its distribution system. These
         transportation customers, using Alagasco as their agent or acting on
         their own, purchase gas directly from producers, marketers or suppliers
         and arrange for delivery of the gas into the Alagasco distribution
         system; Alagasco charges a fee to transport such customer-owned gas
         through its distribution system to the customers' facilities.

         Alagasco's service territory is located in central and parts of north
         Alabama and includes approximately 185 cities and communities in 27
         counties. The aggregate population of the counties served by Alagasco
         is estimated to be 2.3 million. Among the cities served by Alagasco are
         Birmingham, the center of the largest metropolitan area in Alabama, and
         Montgomery, the state capital. During fiscal year 2000, Alagasco served
         an average of 429,368 residential customers and 35,526 commercial,
         industrial and transportation customers. The Alagasco distribution
         system includes approximately 9,370 miles of main and more than 10,980
         miles of service lines, odorization and regulation facilities, and
         customer meters.

         APSC REGULATION: As an Alabama utility, Alagasco is subject to
         regulation by the Alabama Public Service Commission (APSC). Alagasco's
         rate-setting process, Rate Stabilization and Equalization (RSE), was
         established by the APSC in 1983, and extended with modifications in
         1985, 1987 and 1990. On October 7, 1996, RSE was extended, without
         change, for a five-year period through January 1, 2002. Under the terms
         of the extension, RSE will continue after January 1, 2002, unless,
         after notice to the Company and a hearing, the APSC votes to modify or
         discontinue its operation. RSE replaced the traditional utility rate
         case with quarterly reviews and adjustments designed to give Alagasco
         an opportunity to earn a return on average equity at year-end within a
         designated range, which presently is 13.15 percent to 13.65 percent.
         Alagasco has earned at or near its allowed range since fiscal 1990 when
         the APSC modified RSE to include a forward-looking test year and
         approved a temperature adjustment rider to Alagasco's rate tariff.

         Under RSE as extended, the APSC conducts quarterly reviews to
         determine, based on Alagasco's projections and fiscal year-to-date
         performance, whether Alagasco's return on equity for the fiscal year
         will be within the allowed range. Reductions in rates can be made
         quarterly to bring the projected return within the allowed range;
         increases, however, are allowed only once each fiscal year, effective
         December 1, and cannot exceed 4 percent of prior-year revenues. RSE
         limits the utility's equity upon which a return is permitted to 60
         percent of total capitalization and provides for certain cost control
         measures designed to monitor Alagasco's operations and maintenance
         (O&M) expenses. If the change in O&M per customer falls within 1.25
         percentage points above or below the Consumer Price Index for All Urban
         Customers (index range), no adjustment is required. If the change in
         O&M per customer exceeds the index range, three-quarters of the
         difference is returned to customers. To the extent the change is less
         than the index range, the utility benefits by one-half of the
         difference through future rate adjustments.

         The temperature adjustment rider to Alagasco's rate tariff, approved by
         the APSC in 1990, was designed to mitigate the earnings impact of
         variances from normal temperatures. Alagasco performs this real-time
         temperature adjustment calculation monthly, and the adjustments to
         customers' bills are made in the same billing cycle in which the
         weather variation occurs. Substantially all the customers to whom the
         temperature adjustment applies are residential, small commercial and
         small industrial. Alagasco's rate schedules for natural gas
         distribution charges contain a Gas Supply Adjustment (GSA) rider,
         established in 1993, which permits the pass-through to customers of
         changes in the cost of gas supply.

         The APSC approved an Enhanced Stability Reserve (ESR), beginning fiscal
         year 1998, to which Alagasco may charge the full amount of: (1)
         extraordinary O&M expenses resulting from force majeure events such as
         storms,


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         severe weather, and outages, when one or a combination of two such
         events results in more than $200,000 of additional O&M expense during a
         fiscal year; or (2) individual industrial and commercial customer
         revenue losses that exceed $250,000 during the fiscal year, if such
         losses cause Alagasco's return on equity to fall below 13.15 percent.
         The APSC approved the reserve on October 6, 1998, in the amount of $3.9
         million; the maximum approved funding level of the ESR is $4 million.
         Following a year in which a charge against the ESR is made, the APSC
         provides for accretions to the ESR in an amount of no more than $40,000
         monthly until the maximum funding level is achieved.

         GAS SUPPLY: Alagasco's distribution system is connected to and has firm
         transportation contracts with two major interstate pipeline systems -
         Southern Natural Gas Company (Southern) and Transcontinental Gas Pipe
         Line Corporation (Transco). On Southern's system, Alagasco has 251,679
         Mcfd (thousand cubic feet per day) of No-Notice Firm Transportation
         service through October 31, 2008, and 40,000 Mcfd and 92,373 Mcfd of
         Firm Transportation service through April 30, 2005 and October 31,
         2008, respectively. The Transco Firm Transportation contract, which
         expires October 31, 2002, provides for up to 100,000 Mcfd. As a result,
         Alagasco has a peak day firm interstate pipeline transportation
         capacity of 484,052 Mcfd. Alagasco has 12,464,074 Mcf of storage
         capacity on Southern's system, with a maximum withdrawal rate of
         251,679 Mcfd from storage and a maximum injection rate of 95,878 Mcfd
         to storage. Alagasco also operates two liquified natural gas (LNG)
         facilities used to meet peak demand.

         Alagasco purchases gas from various gas producers and marketers,
         including affiliates of Southern and Transco, and from certain
         intrastate producers and marketers. Alagasco has contracts in place to
         purchase up to 306,384 Mcfd of firm supply, of which 232,373 Mcfd is
         supported by firm transportation on the Transco and Southern systems
         and approximately 22,900 Mcfd is purchased at the city gate under
         intrastate firm supply contracts. These firm supply volumes along with
         Alagasco's maximum withdrawal from storage of 251,679 Mcfd and LNG
         peak-shaving capacity of 200,000 Mcfd, give Alagasco a peak day firm
         supply of 758,063 Mcfd. Alagasco also utilizes the Southern pipeline
         systems to access spot market gas in order to supplement its firm
         system supply and serve its industrial and large commercial
         transportation customers. Deliveries of sales and transportation gas
         totaled 108,695 million cubic feet in fiscal year 2000.

         COMPETITION AND RATE FLEXIBILITY: The price of natural gas is a
         significant competitive factor in Alagasco's service territory,
         particularly among large commercial and industrial transportation
         customers. Propane, coal and fuel oil readily are available, and many
         industrial customers have the capability to switch to alternate fuels
         and/or alternate sources of gas. In the residential and small
         commercial and industrial markets, electricity is the principal
         competitor. With the support of the APSC, Alagasco has implemented a
         variety of flexible rate strategies to help it compete for the large
         customers' gas load in the deregulated marketplace. Rate flexibility
         remains critical as the utility faces competition for the large
         customer load. To date, the utility has been effective in utilizing its
         flexible rate strategies to minimize bypass and price-based switching
         to alternate fuels and alternate sources of gas.

         In 1994 Alagasco implemented the P Rate in response to the competitive
         challenge of interstate pipeline capacity release. Under this tariff
         provision, Alagasco releases much of its excess pipeline capacity and
         repurchases it as agent for its transportation customers under 12 month
         contracts. The transportation customers benefit from lower pipeline
         costs. Alagasco's core market customers benefit, as well, since the
         utility uses the revenues received from the P Rate to decrease gas
         costs for its residential and small commercial and industrial
         customers. In fiscal year 2000, approximately 300 of Alagasco's
         transportation customers utilized the P Rate, and the resulting
         reduction in core market gas costs totaled approximately $8 million.

         The Competitive Fuel Clause (CFC) and Transportation Tariff also have
         been important to Alagasco's ability to compete effectively for
         customer load in its service territory. The CFC allows Alagasco to
         adjust large customer rates on a case-by-case basis to compete with
         alternate fuels and alternate sources of gas. The GSA rider to
         Alagasco's tariff allows the Company to recover the reduction in
         charges allowed under the CFC because the retention of any customer,
         particularly large commercial and industrial transportation customers,
         benefits all customers by recovering a portion of the system's fixed
         costs. The Transportation Tariff allows


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         Alagasco to transport gas for customers rather than buy and resell it
         to them. The Transportation Tariff is based on Alagasco's sales profit
         margin, so operating margins are unaffected. During 2000 substantially
         all of Alagasco's large commercial and industrial customer deliveries
         were the transportation of customer-owned gas. In addition, Alagasco
         served as gas purchasing agent for approximately 99 percent of its
         transportation customers. Alagasco also uses long-term special
         contracts as a vehicle for retaining large customer load. At the end of
         fiscal year 2000, 43 of the utility's largest commercial and industrial
         transportation customers were under special contracts of varying
         lengths.

         Natural gas service available to Alagasco customers falls into two
         broad categories: interruptible and firm. Interruptible service
         contractually is subject to interruption by Alagasco for various
         reasons; the most common occurrence is curtailment of industrial
         customers during periods of peak core market heating demand.
         Interruptible service typically is provided to large commercial and
         industrial transportation customers who can reduce their gas
         consumption by adjusting production schedules or by switching to
         alternate fuels for the duration of the service interruption. More
         expensive firm service, on the other hand, generally is not subject to
         interruption and is provided to residential and small commercial and
         industrial customers; these core market customers depend on natural gas
         primarily for space heating.

         GROWTH: Customer growth presents a major challenge for Alagasco, given
         its mature, slow-growth service area. In fiscal year 2000, Alagasco had
         customer growth of less than 1 percent while penetrating 95 percent of
         the new single-family housing market in its service area and 42.5
         percent of the new multi-family housing market. For fiscal year 2001,
         Alagasco will continue its efforts to increase gas usage by focusing on
         conversion prospects and by promoting, in addition to gas furnaces and
         water heaters, other energy-efficient natural gas products such as
         fireplace logs, outdoor gaslights, grills, ovens and cooktops. In
         addition, Alagasco will continue to pursue opportunities to invest in
         revenue-generating or cost-saving projects.

         A vehicle for supplementing Alagasco's normal growth continues to be
         Alagasco's municipal acquisition program. Since 1985, Alagasco has
         acquired 22 municipally owned systems, adding more than 42,000
         customers through initial system purchases and subsequent customer
         additions. Approximately 78 municipal systems remain in Alabama.
         Although Alagasco has not acquired any new municipal gas systems since
         1996, it continues to pursue the purchase of municipal gas systems, and
         company management believes that such acquisitions offer future growth
         opportunities.

         SEASONALITY: Alagasco's gas distribution business is highly seasonal
         since a material portion of the utility's total sales and delivery
         volumes is to space heating customers whose use varies depending upon
         temperature. Alagasco's rate tariff includes a temperature adjustment
         rider for substantially all residential, small commercial and small
         industrial customers which is designed to mitigate the effect of
         departures from normal temperature on Alagasco's earnings. The
         calculation is performed monthly, and adjustments are made to
         customers' bills in the actual month the weather variation occurs.

         ENVIRONMENTAL MATTERS: Alagasco is in the chain of title of eight
         former manufactured gas plant sites and five manufactured gas
         distribution sites. It still owns four of the plant sites and one of
         the distribution sites. An investigation of the sites does not indicate
         the present need for remediation activities. Management expects that,
         should remediation of any such sites be required in the future,
         Alagasco's share of any associated costs will not materially affect the
         results of its operations or financial condition.

         OTHER: For a discussion of risks inherent in the Company's businesses,
         see Management's Discussion and Analysis in the Fiscal Year 2000 Annual
         Report to Shareholders (pages 29 and 30), which is attached, herein, as
         Part IV, Item 14, Exhibit 13.


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-        OIL AND GAS OPERATIONS

         GENERAL: Energen's oil and gas operations focus on increasing
         production and adding proved reserves through the acquisition and
         exploitation of oil and gas properties with varying levels of
         development potential. To a lesser extent, Energen Resources explores
         for and develops new reservoirs, primarily in areas in which it has an
         operating presence. Energen Resources also provides operating services
         in the Black Warrior Basin in Alabama for its partners and third
         parties. All current oil and gas operations are located in the
         continental United States.

         At the end of fiscal year 2000, Energen Resources' inventory of proved
         oil and gas reserves increased to 1.1 trillion cubic feet equivalent,
         as a successful exploitation program added new reserves sufficient to
         replace production. Approximately 95 percent of the company's 1,080.6
         billion cubic feet equivalent (Bcfe) of reserves are located in the San
         Juan Basin in New Mexico, the Black Warrior Basin in Alabama, the
         Permian Basin in west Texas, and the north Louisiana/east Texas region.
         Energen Resources' reserve base is conservative in nature, with
         approximately 87 percent of year-end reserves classified as proved
         developed; in addition, the reserve base is long-lived, with a
         reserves-to-production ratio of 15 at fiscal year-end. Natural gas
         represents approximately 72 percent of Energen Resources' proved
         reserves, with oil and natural gas liquids comprising the balance.

         GROWTH STRATEGY: Energen has completed five years under an aggressive
         strategy to grow its non-regulated oil and gas operations. Since the
         end of fiscal year 1995, Energen Resources has invested approximately
         $510 million in property acquisitions, $185 million in related
         development, and $80 million in exploration and associated development.
         Energen Resources' capital investment for oil and gas activities over
         the five-year period ending September 30, 2005, is expected to range
         from $950 million to $1 billion.

         Energen Resources' approach to the oil and gas business calls for the
         company to pursue onshore North American property acquisitions which
         offer significant amounts of proved undeveloped (PUD) and/or
         behind-pipe reserves as well as operational enhancement potential.
         Energen Resources prefers gas to oil properties, long-lived reserves
         and operated properties that offer multiple pay-zone exploitation
         opportunities; however, Energen Resources does not preclude possible
         acquisitions of properties that otherwise meet its investment
         requirements.

         Following an acquisition, Energen Resources focuses on increasing
         production and reserves through aggressive exploitation of the
         properties' PUD and behind-pipe reserve potential. These exploitation
         activities include development well drilling, behind-pipe
         recompletions, workovers, secondary recovery and operational
         enhancements. Energen Resources prefers to operate its properties in
         order to better control the nature and pace of exploitation activities.
         Energen Resources' exploitation activities can result in the addition
         of new proved reserves as well as serve to reclassify proved
         undeveloped reserves to proved developed reserves.

         Over the last three fiscal years the company's exploitation efforts
         have added approximately 260 Bcfe of proved reserves from the drilling
         of approximately 330 gross development wells and the performance of
         some 360 well recompletions and pay-adds. In fiscal year 2000, Energen
         Resources' successful development wells and other exploitation
         activities added approximately 76 Bcfe of proved reserves. The company
         drilled 136 gross development wells, performed some 145 well
         recompletions and pay-adds, and conducted other performance-related
         enhancements. Energen Resources' production totaled 70.5 Bcfe in fiscal
         2000 and, absent any acquisitions made prior to September 30, 2001, is
         estimated to total 68 Bcfe in fiscal 2001.

         Most of Energen Resources' coalbed methane production generates
         nonconventional fuels tax credits through December 31, 2002, when the
         credits are scheduled to expire. In fiscal 2000, Energen Resources'
         nonconventional fuels tax credits totaled $14.4 million; and, in fiscal
         years 2001 and 2002, Energen Resources expects to generate
         approximately $13 million and $12 million, respectively, of the
         production credits. These credits have been instrumental in Energen
         Resources' successful development of large-scale coalbed methane
         projects in the Black Warrior Basin. As the tax credit expiration date
         approaches, Energen Resources plans to continue to replace the tax
         credits with long-term, revenue-generating property acquisitions and
         related development in a manner that does not negatively affect
         corporate earnings in fiscal year 2003 and beyond.


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         RISK MANAGEMENT: Energen Resources attempts to lower the risk
         associated with its oil and gas business. A key component of the
         company's efforts to manage risk is its acquisition versus exploration
         orientation and its preference for long-lived reserves. To help reduce
         short-term commodity price risk, Energen Resources uses market-driven
         pricing estimates and hedging strategies. In pursuing an acquisition,
         Energen Resources uses in its evaluation models the then-current oil
         and gas futures prices, the prevailing swap curve and, for the
         longer-term, its own pricing assumptions. After a purchase, Energen
         Resources may use futures, swaps and/or fixed-price contracts to lock
         in commodity prices for up to 36 months to help protect targeted
         returns from price volatility. On an on-going basis, Energen Resources
         may hedge up to 80 percent of its flowing production in any given
         fiscal year depending on its pricing outlook.

         As of September 30, 2000, Energen Resources had entered into contracts
         and swaps for 37 Bcf of its fiscal 2001 gas production at an average
         NYMEX price (before basis differentials) of $2.76 per Mcf, 950 MBbl of
         its oil production at an average NYMEX price of $24.32 per barrel and
         150 MBbl of oil production with a collar price of $20.00 to $25.24 per
         barrel. Energen Resources also had basin-specific hedges in place for
         150 MBbl of oil at an average realized price of $23.53 per barrel. In
         addition, the Company had hedged the basis difference on 17.8 Bcf of
         its fiscal 2001 basin-specific production. Subsequent to September 30,
         2000, Energen Resources entered into additional contracts and swaps for
         fiscal year 2001, resulting in a total of 38.3 Bcf of its fiscal 2001
         gas production at an average NYMEX price (before basis differentials)
         of $2.93 per Mcf and 1,188 MBbl of oil production hedged at an average
         NYMEX price of $25.30 per barrel for fiscal year 2001. The Company also
         had hedged basis difference totaling 20.3 Bcf of its fiscal 2001
         basin-specific gas production. The oil collar and basin-specific hedges
         remain unchanged.

         For fiscal 2002, Energen Resources entered into contracts and swaps for
         6 Bcf of its gas production at an average NYMEX price (before basis
         differentials) of $3.19 per Mcf. The Company had hedged the basis
         difference on 6 Bcf of its fiscal 2002 basin-specific gas production.
         Subsequent to September 30, 2000, Energen Resources entered into
         additional contracts and swaps for fiscal year 2002, resulting in a
         total 12.9 Bcf of its gas production hedged at an average NYMEX price
         (before basis differentials) of $4.05 per Mcf. For fiscal 2003, Energen
         Resources entered into contracts and swaps for 1.9 Bcf of its gas
         production at an average NYMEX price of $3.95 with corresponding basis
         swaps. For fiscal 2004, Energen Resources entered into contracts and
         swaps for 1.8 Bcf of its gas production at an average NYMEX price of
         $3.77. For fiscal 2005, Energen Resources entered into contracts and
         swaps for 1.6 Bcf of its gas production at an average NYMEX price of
         $3.75

         In addition to the derivatives described above, the Company has
         three-way pricing, physical sales contracts in place for approximately
         23 percent and 17 percent of its estimated gas production in fiscal
         years 2002 and 2003, respectively. This is more fully described in the
         Fiscal Year 2000 Annual Report to Shareholders, page 29.

         In June 1998, the FASB issued Statement of Financial Accounting
         Standard (SFAS) No. 133, (subsequently amended by SFAS Nos. 137 and
         138), which established new accounting and reporting standards for
         derivative instruments. The Company is required to adopt this statement
         on October 1, 2000. This statement requires the Company to recognize
         all derivatives as either assets or liabilities on the balance sheet
         and measure the effectiveness of the hedges, or the degree that the
         gain (loss) for the hedging instrument offsets the loss (gain) on the
         hedged item, at fair value each reporting period. The effective portion
         of the gain or loss on the derivative instrument will be recognized in
         other comprehensive income as a component of equity until the hedged
         item is recognized in earnings. The ineffective portion of the
         derivative's change in fair value is required to be recognized in
         earnings immediately.

         Energen Resources has fiscal 2001 hedges of 1.3 Bcf of gas and 200 MBbl
         of oil production which will not meet the definition of a cash flow
         hedge under Statement of Financial Accounting Standard (SFAS) No. 133;
         accordingly, the associated contracts outstanding at December 31, 2000,
         will be marked to market, with applicable unrealized gains or losses
         recorded at that time in the Company's results of operations. Such
         derivative instruments are considered by management to be solid
         economic hedges, and though they may cause volatility of interim
         financial results due to technical compliance with SFAS


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<PAGE>   10
No. 133 they are not expected to affect materially the annual operating results
of the Company. (See Item 7a, Quantitative and Qualitative Disclosures About
Market Risk, and the Forward-Looking Statement and Risk in Item 7, Management's
Discussion and Analysis of Results of Operations and Financial Condition, for
further discussion with respect to price and other risk.)

ENVIRONMENTAL MATTERS: Energen Resources is subject to various environmental
regulations. Management believes that Energen Resources is in compliance with
currently applicable standards of the environmental agencies to which it is
subject and that potential environmental liabilities, if any, are minimal. Also,
to the extent that Energen Resources has operating agreements with various joint
venture partners, environmental costs, if any, would be shared proportionately.

OTHER: For a discussion of risks inherent in the Company's businesses, see
Management's Discussion and Analysis in the Fiscal Year 2000 Annual Report to
Shareholders (pages 29 and 30) which is attached herein as Part IV, Item 14,
Exhibit 13.

EMPLOYEES

The Company has 1,401 employees; Alagasco employs 1,195; Energen Resources
employs 195; and Energen's other subsidiaries employ 11. The Company believes
that its relations with its employees are good.

ITEM 2. PROPERTIES

The corporate headquarters of Energen, Alagasco and Energen Resources are
located in leased office space in Birmingham, Alabama. In addition to its
corporate headquarters in Birmingham, Energen Resources maintains leased offices
in Houston and Midland, Texas, in Farmington, New Mexico and in Arcadia,
Louisiana.

The properties of Alagasco consist primarily of its gas distribution system,
which includes more than 9,370 miles of main, more than 10,980 miles of service
lines, odorization and regulation facilities, and customer meters. Alagasco also
has two liquified natural gas facilities, seven division offices, six payment
centers, five district offices, nine service centers, and other related property
and equipment, some of which are leased by Alagasco. For a further description
of Alagasco's properties, see discussion under Item 1-Business.

For a description of Energen Resources' oil and gas properties, see the
discussion under Item 1-Business. Information concerning Energen Resources'
production, reserves and development is included in Note 16, Oil and Gas
Producing Activities (unaudited), to the Consolidated Financial Statements which
is incorporated by reference from the Fiscal Year 2000 Annual Report to
Shareholders and included in Part IV, Item 14, Exhibit 13, herein. The proved
reserve estimates are consistent with comparable reserve estimates filed by
Energen Resources with any federal authority or agency.

ITEM 3. LEGAL PROCEEDINGS

Energen and its affiliates are, from time to time, parties to various pending or
threatened legal proceedings. Certain of these lawsuits include claims for
punitive damages in addition to other specific relief. Based upon information
presently available and in light of available legal and other defenses,
contingent liabilities arising from threatened and pending litigation are not
considered material in relation to the respective financial positions of Energen
and its affiliates. It should be noted, however, that Energen and its affiliates
conduct business in Alabama and other jurisdictions in which the magnitude and
frequency of punitive damage awards may bear little or no relation to
culpability or actual damages thus making it difficult to predict litigation
results.

ITEM 4. SUBMISSION OF MATTERS TO A VOTE OF SECURITY HOLDERS

No matters were submitted to a vote of security holders during the fourth
quarter of fiscal 2000.


                                       9
<PAGE>   11

EXECUTIVE OFFICERS OF THE REGISTRANTS

ENERGEN CORPORATION

<TABLE>
<CAPTION>
       Name                                     Age                               Position(1)
       ----                                     ---                               -----------
<S>                                             <C>               <C>
Wm. Michael Warren, Jr.                         53                Chairman of the Board
                                                                  President and Chief Executive Officer (2)

Geoffrey C. Ketcham                             49                Executive Vice President, Chief Financial
                                                                  Officer and Treasurer(3)

Gary C. Youngblood                              57                President and Chief Operating Officer of
                                                                  Alagasco(4)

James T. McManus                                42                President and Chief Operating Officer of
                                                                  Energen Resources(5)

Dudley C. Reynolds                              47                General Counsel and Secretary(6)


J. David Woodruff, Jr.                          44                Vice President"Legal and Assistant Secretary
                                                                  and Vice President"Corporate Development(7)

Grace B. Carr                                   45                Controller(8)
</TABLE>

NOTES:   (1)      All executive officers of Energen except for Ms. Carr have
                  been employed by Energen or a subsidiary for the past five
                  years. Officers serve at the pleasure of its Board of
                  Directors.

         (2)      Mr. Warren has been employed by the Company in various
                  capacities since 1983. In January 1992 he was elected
                  President and Chief Operating Officer of Energen and all of
                  its subsidiaries, in October 1995 he was elected Chief
                  Executive Officer of Alagasco and Energen Resources, in
                  February 1997 he was elected Chief Executive Officer of
                  Energen, and effective January 1, 1998, he was elected
                  Chairman of the Board of Energen and each of its subsidiaries.
                  Mr. Warren serves as a Director of Energen and each of its
                  subsidiaries.

         (3)      Mr. Ketcham has been employed by the Company in various
                  capacities since 1981. He has served as Executive Vice
                  President, Chief Financial Officer and Treasurer of Energen
                  and each of its subsidiaries since April 1991.

         (4)      Mr. Youngblood has been employed by the Company in various
                  capacities since 1969. He was elected Executive Vice President
                  of Alagasco in October 1993, Chief Operating Officer of
                  Alagasco in October 1995, and President of Alagasco in April
                  1997.

         (5)      Mr. McManus has been employed by the Company in various
                  capacities since 1986. He was elected Vice President"Finance
                  and Corporate Development of Energen and Vice
                  President"Finance and Planning of Alagasco in April 1991. He
                  was elected Executive Vice President and Chief Operating
                  Officer of Energen Resources in October 1995 and President of
                  Energen Resources in April 1997.

         (6)      Mr. Reynolds has been employed by the Company in various
                  capacities since 1980. He has served as General Counsel and
                  Secretary of Energen and each of its subsidiaries since April
                  1991.


                                       10
<PAGE>   12

         (7)      Mr. Woodruff has been employed by the Company in various
                  capacities since 1986. He has served as Vice President"Legal
                  and Assistant Secretary of Energen and each of its
                  subsidiaries since April 1991 and as Vice President"Corporate
                  Development of Energen since October 1995.

         (8)      Ms. Carr was employed by the Company in various capacities
                  from January 1985 to April 1989. She was not employed from
                  April 1989 through December 1997. She was elected Controller
                  of Energen in January 1998.


                                       11
<PAGE>   13

PART II

ITEM 5. MARKET FOR REGISTRANT'S COMMON STOCK AND RELATED STOCKHOLDER MATTERS

The information regarding Energen's common stock and the frequency and amount of
dividends paid during the past two years with respect to such stock is
incorporated by reference from the Fiscal Year 2000 Annual Report to
Shareholders, page 30, and is included in Part IV, Item 14, Exhibit 13, herein.
At December 8, 2000, there were approximately 8,600 holders of record of
Energen's common stock. For restrictions on Energen's present and future ability
to pay dividends, see Note 3 to the Consolidated Financial Statements which is
incorporated by reference from the Fiscal Year 2000 Annual Report to
Shareholders and included in Part IV, Item 14, Exhibit 13, herein.

At the date of this filing, Energen Corporation owns all the issued and
outstanding common stock of Alabama Gas Corporation.

ITEM 6. SELECTED FINANCIAL DATA

The information regarding selected financial data is incorporated by reference
from the Fiscal Year 2000 Annual Report to Shareholders, pages 56-57, and is
included in Part IV, Item 14, Exhibit 13, herein.

ITEM 7. MANAGEMENT'S DISCUSSION AND ANALYSIS OF RESULTS OF OPERATIONS AND
        FINANCIAL CONDITION

This information is incorporated by reference from the Fiscal Year 2000 Annual
Report to Shareholders, pages 23-30, and is included in Part IV, Item 14,
Exhibit 13, herein.

ITEM 7A. QUANTITATIVE AND QUALITATIVE DISCLOSURES ABOUT MARKET RISK

Energen Resources' major market risk exposure is in the pricing applicable to
its oil, natural gas and natural gas liquids production. Historically, prices
received have been volatile because of seasonal weather patterns, national
supply and demand factors and general economic conditions. Crude oil prices are
also affected by quality differentials, by worldwide political developments and
by actions of the Organization of Petroleum Exporting Countries. Basis
differentials, like the underlying commodity prices, can be volatile because of
regional supply and demand factors, including seasonal factors and the
availability and price of transportation to consuming areas.

Energen Resources enters into derivative commodity instruments to hedge its
exposure to oil and gas price fluctuations. Such instruments include regulated
natural gas and crude oil futures contracts traded on the New York Mercantile
Exchange and over-the-counter swaps and basis hedges with major energy
derivative product specialists. All hedge transactions are subject to the
Company's risk management policy, approved by the Board of Directors, which does
not permit speculative positions. These transactions have been accounted for
under the hedge method of accounting. Under this method, any unrealized gains
and losses are recorded as a receivable/payable with a corresponding deferred
gain/loss. Realized gains and losses are deferred as liabilities or assets until
the revenues from the related hedged volumes are recognized in the income
statement. Cash flows from derivative instruments are recognized as incurred
through changes in working capital. The Company had current deferred hedging
losses of $83.5 million and $16.5 million included in prepayments and other on
the consolidated balance sheet at September 30, 2000 and 1999, respectively. The
Company had non-current deferred hedging losses of $5.9 million included in
deferred charges and other on the consolidated balance sheet at September 30,
2000. In fiscal 2001, the Company is required to adopt Statement of Financial
Accounting Standards No. 133, Accounting for Derivative Instruments and Hedging
Activities, as amended, which establishes new accounting and reporting standards
for derivatives.

The Company has prepared a sensitivity analysis to evaluate the hypothetical
effect that changes in the market value of crude oil and natural gas may have on
the fair value of its derivative instruments. This analysis measured


                                       12
<PAGE>   14

the impact on the commodity derivative instruments and, thereby, did not
consider the underlying exposure related to the commodity. At September 30, 2000
and 1999, the Company estimated that a 10 percent change in the underlying
commodities prices would have resulted in a $23.6 million and a $12.1 million,
respectively, change in the fair value of open derivative contracts; however,
gains and losses on derivative contracts are expected to be similarly offset by
sales at the spot market price. Due to the short duration of the contracts, time
value of money was ignored. The hypothetical change in fair value was calculated
by multiplying the difference between the hypothetical price and the contractual
price by the contractual volumes and did not include the variance in basis
difference or the impact of related taxes on actual cash prices.

ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA

The information required by this item for Energen Corporation and subsidiaries
is incorporated by reference from the Fiscal Year 2000 Annual Report to
Shareholders and is included in Part IV, Item 14, Exhibit 13, herein. The
information required by this item for Alabama Gas Corporation is contained in
Part IV, Item 14, herein.

ITEM 9. CHANGES IN AND DISAGREEMENTS WITH ACCOUNTANTS ON ACCOUNTING AND
        FINANCIAL DISCLOSURE

None


                                       13
<PAGE>   15

PART III

ITEM 10. DIRECTORS AND EXECUTIVE OFFICERS OF THE REGISTRANTS

Information regarding the executive officers of Energen is included in Part I.
The other information required by Item 10 is incorporated herein by reference
from Energen's definitive proxy statement for the Annual Meeting of Shareholders
to be held January 24, 2001. The proxy statement will be filed on or about
December 18, 2000.

ITEM 11. EXECUTIVE COMPENSATION

The information regarding executive compensation is incorporated herein by
reference from Energen's definitive proxy statement for the Annual Meeting of
Shareholders to be held January 24, 2001.

ITEM 12. SECURITY OWNERSHIP OF CERTAIN BENEFICIAL OWNERS AND MANAGEMENT

A. SECURITY OWNERSHIP OF CERTAIN BENEFICIAL OWNERS

         The information regarding the security ownership of the beneficial
         owners of more than five percent of Energen's common stock is
         incorporated herein by reference from Energen's definitive proxy
         statement for the Annual Meeting of Shareholders to be held January 24,
         2001.

B. SECURITY OWNERSHIP OF MANAGEMENT

         The information regarding the security ownership of management is
         incorporated herein by reference from Energen's definitive proxy
         statement for the Annual Meeting of Shareholders to be held January 24,
         2001.

ITEM 13. CERTAIN RELATIONSHIPS AND RELATED TRANSACTIONS

The information regarding certain relationships and related transactions is
incorporated herein by reference from Energen's definitive proxy statement for
the Annual Meeting of Shareholders to be held January 24, 2001.


                                       14
<PAGE>   16

PART IV

ITEM 14. EXHIBITS, FINANCIAL STATEMENT SCHEDULES, AND REPORTS ON FORM 8-K

A. DOCUMENTS FILED AS PART OF THIS REPORT

         (1)      FINANCIAL STATEMENTS

                  The financial statements listed in the accompanying Index to
                  Financial Statements and Financial Statement Schedules are
                  filed as part of this report and are included in Part IV, Item
                  14, Exhibit 13, herein.

         (2)      FINANCIAL STATEMENT SCHEDULES

                  The financial statement schedules listed in the accompanying
                  Index to Financial Statements and Financial Statement
                  Schedules are filed as part of this report.

         (3)      EXHIBITS

                  The exhibits listed on the accompanying Index to Exhibits are
                  filed as part of this report.

B. REPORTS ON FORM 8-K

         None.


                                       15
<PAGE>   17

                                    SIGNATURE

Pursuant to the requirements of Section 13 or 15(d) of the Securities and
Exchange Act of 1934, the Registrants have duly caused this report to be signed
on their behalf by the undersigned thereunto duly authorized.

                               ENERGEN CORPORATION
                                  (Registrant)

                             ALABAMA GAS CORPORATION
                                  (Registrant)



    December 8, 2000             /s/ Wm. Michael Warren, Jr.
------------------------         -----------------------------------------------
        DATE                     Wm. Michael Warren, Jr.
                                 Chairman, President and Chief Executive Officer
                                 of Energen Corporation, Chairman and Chief
                                 Executive Officer of Alabama Gas Corporation


                                       16
<PAGE>   18

                                   SIGNATURES

Pursuant to the requirements of the Securities and Exchange Act of 1934, this
report has been signed by the following persons on behalf of the Registrants and
in the capacities and on the dates indicated:


<TABLE>
<S>                              <C>
     December 8, 2000            /s/ Wm. Michael Warren, Jr.
---------------------------      --------------------------------------------------
         DATE                    Wm. Michael Warren, Jr.
                                 Chairman, President and Chief Executive Officer of
                                 Energen Corporation, Chairman and Chief Executive
                                 Officer of Alabama Gas Corporation


     December 8, 2000            /s/ Geoffrey C. Ketcham
---------------------------      --------------------------------------------------
         DATE                    Geoffrey C. Ketcham
                                 Executive Vice President, Chief Financial Officer
                                 and Treasurer of Energen Corporation  and Alabama
                                 Gas Corporation


    December 8, 2000             /s/ Grace B. Carr
---------------------------      --------------------------------------------------
         DATE                    Grace B. Carr
                                 Controller of Energen Corporation


     December 8, 2000            /s/Paula H. Rushing
---------------------------      --------------------------------------------------
         DATE                    Paula H. Rushing
                                 Vice President--Finance of Alabama Gas
                                 Corporation


    December 8, 2000             /s/ J. Mason Davis, Jr.
---------------------------      --------------------------------------------------
         DATE                    J. Mason Davis, Jr.
                                 Director


    December 8, 2000             /s/ Julian W. Banton
---------------------------      --------------------------------------------------
         DATE                    Julian W. Banton
                                 Director


     December 8, 2000            /s/ James S. M. French
---------------------------      --------------------------------------------------
         DATE                    James S. M. French
                                 Director


     December 8, 2000            /s/ T. Michael Goodrich
---------------------------      --------------------------------------------------
         DATE                    T. Michael Goodrich
                                 Director


     December 8, 2000            /s/ Stephen A. Snider
---------------------------      --------------------------------------------------
         DATE                    Stephen A. Snider
                                 Director
</TABLE>


                                       17
<PAGE>   19

                               ENERGEN CORPORATION
                             ALABAMA GAS CORPORATION
                          INDEX TO FINANCIAL STATEMENTS
                        AND FINANCIAL STATEMENT SCHEDULES

                                   ITEM 14(A)

<TABLE>
<CAPTION>
                                                                                             Reference Page
                                                                                            ----------------
                                                                                                       2000
                                                                                            2000      Annual
                                                                                            10-K      Report
                                                                                            ----      ------
<S>                                                                                         <C>       <C>
1.   Financial Statements

     ENERGEN CORPORATION

              Report of Independent Accountants.......................................                  55

              Consolidated Statements of Income for the years ended
              September 30, 2000, 1999 and 1998.......................................                  31

              Consolidated Balance Sheets as of September 30, 2000 and 1999...........                  32

              Consolidated Statements of Shareholders' Equity for the years
              ended September 30, 2000, 1999 and 1998.................................                  34

              Consolidated Statements of Cash Flows for the years ended
              September 30, 2000, 1999 and 1998.......................................                  35

              Notes to Consolidated Financial Statements..............................                  36

     ALABAMA GAS CORPORATION

              Report of Independent Accountants.......................................       23

              Statements of Income for the years ended
              September 30, 2000, 1999 and 1998.......................................       24

              Balance Sheets as of September 30, 2000 and 1999........................       25

              Statements of Shareholder's Equity for the years ended
              September 30, 2000, 1999 and 1998.......................................       27

              Statements of Cash Flows for the years ended
              September 30, 2000, 1999 and 1998.......................................       28

              Notes to Financial Statements...........................................       29
</TABLE>


                                       18
<PAGE>   20

<TABLE>
<CAPTION>
                                                                                             Reference Page
                                                                                            ----------------
                                                                                                       2000
                                                                                            2000      Annual
                                                                                            10-K      Report
                                                                                            ----      ------
<S>                                                                                         <C>       <C>
2.   Financial Statement Schedules

     ENERGEN CORPORATION

              Report of Independent Accountants on Financial Statement Schedule.......       38

              Schedule II     Valuation and Qualifying Accounts.......................       39

     ALABAMA GAS CORPORATION

              Schedule II     Valuation and Qualifying Accounts.......................       40
</TABLE>

Schedules other than those listed above are omitted because they are not
required or not applicable, or the required information is shown in the
financial statements or notes thereto.


                                       19
<PAGE>   21

                               ENERGEN CORPORATION
                             ALABAMA GAS CORPORATION
                                INDEX TO EXHIBITS
                                  ITEM 14(A)(3)

<TABLE>
<CAPTION>
Exhibit
Number                            Description
-------                           -----------
<S>      <C>
*3(a)    Restated Certificate of Incorporation of Energen Corporation
         (composite, as amended February 2, 1998) which was filed as Exhibit
         3(a) to Energen's Annual Report on Form 10-K for the year ended
         September 30, 1998 (File No. 1-7810)

*3(b)    Articles of Amendment to Restated Certificate of Incorporation of
         Energen, designating Series 1998 Junior Participating Preferred Stock
         (July 27, 1998) which was filed as Exhibit 4(b) to Energen's Post
         Effective Amendment No. 1 to Registration Statement on Form S-3
         (Registration No. 333-00395)

*3(c)    Bylaws of Energen Corporation (as amended through July 22, 1998) which
         was filed as Exhibit 3(c) to Energen's Annual Report on Form 10-K for
         the year ended September 30, 1998 (File No. 1-7810)

*3(d)    Articles of Amendment and Restatement of the Articles of Incorporation
         of Alabama Gas Corporation, dated September 27, 1995, which was filed
         as Exhibit 3(i) to the Registrant's Annual Report on Form 10-K for the
         year ended September 30, 1995 (file No. 1-7810)

*3(e)    Bylaws of Alabama Gas Corporation (as amended through July 22, 1998)
         which was filed as Exhibit 3(e) to Energen's Annual Report on Form 10-K
         for the year ended September 30, 1998 (File No. 1-7810)

*4(a)    Rights Agreement, dated as of July 27, 1998, between Energen
         Corporation and First Chicago Trust Company of New York, Rights Agent,
         which was filed as Exhibit 1 to Energen's Registration Statement on
         Form 8-A, dated July 10, 1998 (File No. 1-7810)

*4(b)    Indenture, dated as of January 1, 1992, between Energen Corporation and
         Boatmen's Trust Company, Trustee, which was filed as Exhibit 4 to
         Energen's Amendment No. 1 to Registration Statement on Form S-3
         (Registration No. 33-44936)

*4(c)    First Supplemental Indenture, dated as of September 5, 1997, between
         Energen Corporation and The Bank of New York, Trustee, to Indenture
         dated as of January 1, 1992, which was filed as Exhibit 4(a) to the
         Registrant's Quarterly Report on Form 10-Q for the quarter ended
         December 31, 1997 (File No. 1-7810)

*4(d)    Indenture, dated as of March 1, 1993, between Energen Corporation and
         Boatmen's Trust Company, Trustee, which was filed as Exhibit 4 to
         Energen's Registration Statement on Form S-3 (Registration No.
         33-25435)

*4(e)    First Supplemental Indenture, dated as of September 5, 1997, between
         Energen Corporation and The Bank of New York, Trustee, to Indenture
         dated as of March 1, 1993, which was filed as Exhibit 4(b) to the
         Registrant's Quarterly Report on Form 10-Q for the quarter ended
         December 31, 1997 (File No. 1-7810)

*4(f)    Form of Indenture between Energen Corporation and The Bank of New York,
         as Trustee, which was dated as of September 1, 1996, and which was
         filed as Exhibit 4(i) to the Registrant's Registration Statement on
         Form S-3 (Registration No. 333-11239)
</TABLE>


                                       20
<PAGE>   22

<TABLE>
<S>      <C>
*4(g)    Indenture dated as of November 1, 1993, between Alabama Gas Corporation
         and NationsBank of Georgia, National Association, Trustee, which was
         filed as Exhibit 4(k) to Alabama Gas' Registration Statement on Form
         S-3 (Registration No. 33-70466)

*10(a)   Form of Service Agreement Under Rate Schedule CSS (No. S10710), between
         Southern Natural Gas Company and Alabama Gas Corporation which was
         filed as Exhibit 10(a) to Energen's Annual Report on Form 10-K for the
         year ended September 30, 1993 (File No. 1-7810)

*10(b)   Form of Service Agreement Under Rate Schedule FT-NN (No. 866941),
         between Southern Natural Gas Company and Alabama Gas Corporation which
         was filed as Exhibit 10(c) to Energen's Annual Report on Form 10-K for
         the year ended September 30, 1993 (File No. 1-7810)

 10(c)   Form of Executive Retirement Supplement Agreement between Energen
         Corporation and it's executive officers (as revised October 2000)

 10(d)   Form of Addendum to Executive Retirement Supplement Agreement between
         Energen Corporation and it's executive officers

*10(e)   Form of Severance Compensation Agreement between Energen Corporation
         and it's executive officers which was filed as Exhibit 10(d) to
         Energen's Annual Report on Form 10-K for the year ended September 30,
         1999 (File No. 1-7810)

*10(f)   Energen Corporation 1988 Stock Option Plan (as amended November 25,
         1997) which was filed as Exhibit 10(e) to Energen's Annual Report on
         Form 10-K for the year ended September 30, 1998 (File No. 1-7810)

*10(g)   Energen Corporation 1992 Long-Range Performance Share Plan (as amended
         effective October 1, 1999) which was filed as Exhibit 10(f) to
         Energen's Annual Report on Form 10-K for the year ended September 30,
         1999 (File No. 1-7810)

 10(h)   Energen Corporation 1997 Stock Incentive Plan (as amended effective
         October 1, 2000)

*10(i)   Energen Corporation 1997 Deferred Compensation Plan (as amended
         effective October 1, 1999) which was filed as Exhibit 10(h) to
         Energen's Annual Report on Form 10-K for the year ended September 30,
         1999 (File No. 1-7810)

*10(j)   Energen Corporation 1992 Directors Stock Plan (as amended April 25,
         1997) which was filed as Exhibit 10(i) to Energen's Annual Report on
         Form 10-K for the year ended September 30, 1998 (File No. 1-7810)

*10(k)   Energen Corporation Annual Incentive Compensation Plan, Revised 5/90,
         as amended effective October 1, 1993, which was filed as Exhibit 10(m)
         to Energen's Annual Report on Form 10-K for the year ended September
         30, 1994 (File No. 1-7810)

 10(l)   Energen Corporation Officer Split Dollar Life Insurance Plan, effective
         October 1, 1999

 10(m)   Form of Split Dollar Life Insurance Plan Agreement under Energen
         Corporation Officer Split Dollar Life Insurance Plan

 10(n)   Officer Split Dollar Tax Matters Agreement

 13      Energen Corporation Fiscal Year 2000 Annual Report to Shareholders
         (pages 23-59)
</TABLE>


                                       21
<PAGE>   23

<TABLE>
 <S>     <C>
 21      Subsidiaries of Energen Corporation

 23      Consent of Independent Accountants (Energen Corporation)

 27.1    Financial Data Schedule of Energen Corporation (for SEC purposes only)

 27.2    Financial Data Schedule of Alabama Gas Corporation (for SEC purposes
         only)
</TABLE>

*Incorporated by reference


                                       22
<PAGE>   24


REPORT OF INDEPENDENT ACCOUNTANTS

TO THE BOARD OF DIRECTORS OF ALABAMA GAS CORPORATION:

In our opinion, the accompanying financial statements of Alabama Gas Corporation
listed in the index appearing under Part IV, Item 14(a)(1) on page 18 of this
Form 10-K present fairly, in all material respects, the financial position of
Alabama Gas Corporation at September 30, 2000 and 1999, and the results of its
operations and cash flows for each of the three years in the period ended
September 30, 2000, in conformity with accounting principles generally accepted
in the United States of America. In addition, in our opinion, the financial
statement schedule listed in the index appearing under Part IV, Item 14(a)(2) on
page 19 of this Form 10-K presents fairly, in all material respects, the
information set forth therein when read in conjunction with the related
financial statements. These financial statements and the financial statement
schedule are the responsibility of the Company's management; our responsibility
is to express an opinion on these financial statements and the financial
statement schedule based on our audits. We conducted our audits of these
statements in accordance with auditing standards generally accepted in the
United States of America, which require that we plan and perform the audit to
obtain reasonable assurance about whether the financial statements are free of
material misstatement. An audit includes examining, on a test basis, evidence
supporting the amounts and disclosures in the financial statements, assessing
the accounting principles used and significant estimates made by management, and
evaluating the overall financial statement presentation. We believe that our
audits provide a reasonable basis for our opinion.




PricewaterhouseCoopers LLP
Birmingham, Alabama
October 25, 2000


                                       23
<PAGE>   25


STATEMENTS OF INCOME
ALABAMA GAS CORPORATION



<TABLE>
<CAPTION>
=================================================================================================
YEARS ENDED SEPTEMBER 30, (IN THOUSANDS)              2000              1999              1998
-------------------------------------------------------------------------------------------------

<S>                                                 <C>               <C>               <C>
OPERATING REVENUES                                  $ 366,161         $ 325,554         $ 369,940
-------------------------------------------------------------------------------------------------

OPERATING EXPENSES
Cost of gas                                           155,841           126,264           176,124
Operations and maintenance                            104,206           100,478            98,897
Depreciation                                           28,708            26,730            25,153
Income taxes
   Current                                             16,711            15,748            16,801
   Deferred, net                                       (1,939)           (2,137)           (4,932)
   Deferred investment tax credits, net                  (448)             (448)             (469)
Taxes, other than income taxes                         28,343            25,517            28,103
-------------------------------------------------------------------------------------------------

       Total operating expenses                       331,422           292,152           339,677
-------------------------------------------------------------------------------------------------

OPERATING INCOME                                       34,739            33,402            30,263
-------------------------------------------------------------------------------------------------

OTHER INCOME (EXPENSE)
Allowance for funds used during construction            1,172               374               400
Other, net                                                281              (113)              145
-------------------------------------------------------------------------------------------------

       Total other income                               1,453               261               545
-------------------------------------------------------------------------------------------------

INTEREST CHARGES
Interest on long-term debt                              8,542             8,614             8,843
Other interest expense                                  1,328             1,752             1,378
-------------------------------------------------------------------------------------------------

       Total interest charges                           9,870            10,366            10,221
-------------------------------------------------------------------------------------------------

NET INCOME                                          $  26,322         $  23,297         $  20,587
=================================================================================================
</TABLE>


The accompanying Notes to Financial Statements are an integral part of these
statements.


                                       24
<PAGE>   26


BALANCE SHEETS
ALABAMA GAS CORPORATION


<TABLE>
<CAPTION>
======================================================================
AS OF SEPTEMBER 30, (IN THOUSANDS)           2000              1999
======================================================================
<S>                                        <C>               <C>
ASSETS
PROPERTY, PLANT AND EQUIPMENT
Utility plant                              $ 709,004         $ 645,596
Less accumulated depreciation                353,997           328,775
----------------------------------------------------------------------

   Utility plant, net                        355,007           316,821
----------------------------------------------------------------------

Other property, net                              241               298
----------------------------------------------------------------------

CURRENT ASSETS
Cash                                             866               533
Accounts receivable
   Gas                                        48,300            37,157
   Merchandise                                 2,192             2,283
   Other                                       1,472             1,966
   Affiliated companies                           --            20,654
   Allowance for doubtful accounts            (5,800)           (4,532)
Inventories, at average cost
   Storage gas inventory                      36,437            24,722
   Materials and supplies                      5,400             5,024
   Liquified natural gas in storage            3,267             3,318
Deferred gas costs                             3,556             2,305
Deferred income taxes                         12,360            11,621
Prepayments and other                          3,438             4,652
----------------------------------------------------------------------

     Total current assets                    111,488           109,703
----------------------------------------------------------------------

DEFERRED CHARGES AND OTHER ASSETS              4,546             3,833
----------------------------------------------------------------------

TOTAL ASSETS                               $ 471,282         $ 430,655
======================================================================
</TABLE>


The accompanying Notes to Financial Statements are an integral part of these
statements.


                                       25
<PAGE>   27


BALANCE SHEETS
ALABAMA GAS CORPORATION


<TABLE>
<CAPTION>
=====================================================================================
AS OF SEPTEMBER 30, (IN THOUSANDS, EXCEPT SHARE DATA)          2000            1999
=====================================================================================

<S>                                                          <C>             <C>
CAPITAL AND LIABILITIES
CAPITALIZATION
Common shareholder's equity
   Common stock, $0.01 par value; 3,000,000 shares
      authorized, 1,972,052 shares outstanding at
      September 30, 2000 and 1999, respectively              $     20        $     20
   Premium on capital stock                                    31,682          31,682
   Capital surplus                                              2,802           2,802
   Retained earnings                                          164,767         143,502
-------------------------------------------------------------------------------------

   Total common shareholder's equity                          199,271         178,006
Long-term debt                                                115,000         119,650
-------------------------------------------------------------------------------------

       Total capitalization                                   314,271         297,656
-------------------------------------------------------------------------------------

CURRENT LIABILITIES
Long-term debt due within one year                              4,650              --
Notes payable to banks                                         20,500              --
Accounts payable
   Trade                                                       39,376          36,985
   Affiliated companies                                         1,156              --
Accrued taxes                                                  21,621          18,799
Customers' deposits                                            15,512          16,301
Amounts due customers                                          14,914          18,576
Accrued wages and benefits                                      9,221           9,663
Other                                                          10,230          10,847
-------------------------------------------------------------------------------------

       Total current liabilities                              137,180         111,171
-------------------------------------------------------------------------------------

DEFERRED CREDITS AND OTHER LIABILITIES
Deferred income taxes                                          15,938          16,689
Accumulated deferred investment tax credits                     1,765           2,213
Regulatory liability                                            1,352           2,112
Customer advances for construction and other                      776             814
-------------------------------------------------------------------------------------

       Total deferred credits and other liabilities            19,831          21,828
-------------------------------------------------------------------------------------

TOTAL CAPITAL AND LIABILITIES                                $471,282        $430,655
=====================================================================================
</TABLE>


The accompanying Notes to Financial Statements are an integral part of these
statements.


                                       26
<PAGE>   28

STATEMENTS OF SHAREHOLDER'S EQUITY
ALABAMA GAS CORPORATION


<TABLE>
<CAPTION>
=================================================================================================================

(IN THOUSANDS, EXCEPT SHARE AMOUNTS)
=================================================================================================================
                                                     COMMON STOCK
                                                  ------------------
                                                  NUMBER OF     PAR      PREMIUM ON       CAPITAL      RETAINED
                                                    SHARES     VALUE    CAPITAL STOCK     SURPLUS      EARNINGS
-----------------------------------------------------------------------------------------------------------------

<S>                                              <C>          <C>       <C>              <C>           <C>
BALANCE AT SEPTEMBER 30, 1997                     1,972,052   $  20        $ 31,682      $   2,802     $ 106,894
Net income                                                                                                20,587
Cash dividends                                                                                            (7,276)
-----------------------------------------------------------------------------------------------------------------

BALANCE AT SEPTEMBER 30, 1998                     1,972,052      20          31,682          2,802       120,205
Net income                                                                                                23,297
-----------------------------------------------------------------------------------------------------------------

BALANCE AT SEPTEMBER 30, 1999                     1,972,052      20          31,682          2,802       143,502
Net income                                                                                                26,322
Cash dividends                                                                                            (5,057)
-----------------------------------------------------------------------------------------------------------------

BALANCE AT SEPTEMBER 30, 2000                     1,972,052   $  20       $  31,682      $   2,802     $ 164,767
=================================================================================================================
</TABLE>


The accompanying Notes to Financial Statements are an integral part of these
statements.


                                       27
<PAGE>   29



STATEMENTS OF CASH FLOWS
ALABAMA GAS CORPORATION



<TABLE>
<CAPTION>
=============================================================================================================

YEARS ENDED SEPTEMBER 30, (IN THOUSANDS)                            2000             1999             1998
=============================================================================================================

<S>                                                               <C>              <C>              <C>
OPERATING ACTIVITIES
Net income                                                        $ 26,322         $ 23,297         $ 20,587
Adjustments to reconcile net income to net cash
  provided by (used in) operating activities:
    Depreciation and amortization                                   28,708           26,730           25,153
    Deferred income taxes, net                                      (1,939)          (2,137)          (4,932)
    Deferred investment tax credits                                   (448)            (448)            (469)
    Net change in:
       Accounts receivable                                          (9,290)          (4,182)           3,693
       Inventories                                                 (12,040)          (2,913)           4,237
       Deferred gas costs                                           (1,251)            (531)             738
       Accounts payable - gas purchases                              2,559           14,115           (7,466)
       Accounts payable - trade                                       (168)            (347)           1,760
       Amounts due customers                                        (3,662)           6,695            4,723
       Other current assets and liabilities                          1,617            1,198            9,129
    Other, net                                                      (1,663)            (583)             530
-------------------------------------------------------------------------------------------------------------

       Net cash provided by operating activities                    28,745           60,894           57,683
-------------------------------------------------------------------------------------------------------------

INVESTING ACTIVITIES
Additions to property, plant and equipment                         (65,684)         (45,390)         (53,581)
Net advances from (to) parent company                               21,811          (23,392)          (2,246)
Proceeds from sale of assets                                            --           27,000               --
Other, net                                                              18              549               62
-------------------------------------------------------------------------------------------------------------

       Net cash used in investing activities                       (43,855)         (41,233)         (55,765)
-------------------------------------------------------------------------------------------------------------

FINANCING ACTIVITIES
Payment of dividends on common stock                                (5,057)              --           (7,276)
Reduction of long-term debt                                             --           (5,350)              --
Net change in short-term debt                                       20,500          (15,000)           4,000
-------------------------------------------------------------------------------------------------------------

       Net cash provided by (used in) financing activities          15,443          (20,350)          (3,276)
-------------------------------------------------------------------------------------------------------------

Net change in cash and cash equivalents                                333             (689)          (1,358)
Cash and cash equivalents at beginning of period                       533            1,222            2,580
-------------------------------------------------------------------------------------------------------------

Cash and cash equivalents at end of period                        $    866         $    533         $  1,222
=============================================================================================================
</TABLE>


The accompanying Notes to Financial Statements are an integral part of these
statements.


                                       28
<PAGE>   30



NOTES TO FINANCIAL STATEMENTS

1.       SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES


Alabama Gas Corporation (Alagasco), a wholly-owned subsidiary of Energen
Corporation (the Company), is the largest natural gas distribution utility in
the State of Alabama, serving customers primarily in central and parts of north
Alabama. The following is a description of its significant accounting policies
and practices.

A.       UTILITY PLANT AND DEPRECIATION: Property, plant and equipment is stated
         at cost. The cost of utility plant includes an allowance for funds used
         during construction. Maintenance is charged for the cost of normal
         repairs and the renewal or replacement of an item of property which is
         less than a retirement unit. When property which represents a
         retirement unit is replaced or removed, the cost of such property is
         credited to utility plant and, together with the cost of removal less
         salvage, is charged to the accumulated reserve for depreciation.
         Depreciation is provided on the straight-line method over the estimated
         useful lives of utility property at rates established by the Alabama
         Public Service Commission (APSC). Approved depreciation rates averaged
         approximately 4.5 percent in 2000 and 1999 and 4.4 percent in 1998.

B.       INVENTORIES: Inventories, which consist primarily of gas stored
         underground, are stated at average cost.

C.       OPERATING REVENUE AND GAS COSTS: In accordance with industry practice,
         Alagasco records natural gas distribution revenues on a monthly- and
         cycle-billing basis. The commodity cost of purchased gas applicable to
         gas delivered to customers but not yet billed under the cycle-billing
         method is deferred as a current asset.

D.       REGULATORY ACCOUNTING: Alagasco is subject to the provisions of
         Statement of Financial Accounting Standard (SFAS) No. 71, Accounting
         for the Effects of Certain Types of Regulation. In general, SFAS No. 71
         allows utilities to capitalize or defer certain costs or revenues,
         based upon approvals received from regulatory authorities, to be
         recovered from or refunded to customers in future periods.

E.       INCOME TAXES: Alagasco files a consolidated federal income tax return
         with its parent. Consolidated federal income taxes are allocated to the
         appropriate subsidiaries using the separate return method. Alagasco
         uses the liability method of accounting for income taxes in accordance
         with SFAS No. 109, Accounting for Income Taxes. Under this method, a
         deferred tax liability or asset is recognized for the estimated future
         tax effects attributable to temporary differences. Deferred tax assets
         and liabilities are measured using enacted tax rates expected to apply
         to taxable income in the years to which those temporary differences are
         expected to be recovered or settled. Investment tax credits have been
         deferred and are being amortized over the lives of the related assets.

F.       CASH EQUIVALENTS: Alagasco includes highly liquid marketable securities
         and debt instruments purchased with a maturity of three months or less
         in cash equivalents.

G.       ESTIMATES: The preparation of financial statements in conformity with
         generally accepted accounting principles requires management to make
         estimates and assumptions that affect the reported amounts of assets
         and liabilities at the date of the financial statements and the
         reported amount of revenues and expenses during the reporting period.
         Actual results could differ from those estimates.

2.       REGULATORY MATTERS


As an Alabama utility, Alagasco is subject to regulation by the APSC which, in
1983, established the Rate Stabilization and Equalization (RSE) rate-setting
process. RSE was extended with modifications in 1985, 1987 and 1990. On October
7, 1996, RSE was extended, without change, for a five-year period through
January 1, 2002. Under the terms of that extension, RSE will continue after
January 1, 2002, unless, after notice to the Company and a hearing, the
Commission votes to either modify or discontinue its operation. Under RSE as
extended, the APSC conducts quarterly reviews to determine, based on Alagasco's
projections and fiscal year-to-date performance, whether Alagasco's return on
equity for the fiscal year will be within the allowed range of 13.15


                                       29
<PAGE>   31

percent to 13.65 percent. Reductions in rates can be made quarterly to bring the
projected return within the allowed range; increases, however, are allowed only
once each fiscal year, effective December 1, and cannot exceed 4 percent of
prior-year revenues. RSE limits the utility's equity upon which a return is
permitted to 60 percent of total capitalization and provides for certain cost
control measures designed to monitor Alagasco's operations and maintenance (O&M)
expense. Under the inflation-based cost control measurement established by the
APSC, if a change in O&M expense per customer falls within 1.25 percentage
points above or below the Consumer Price Index For All Urban Customers (index
range), no adjustment is required. If the change in O&M expense per customer
exceeds the index range, three-quarters of the difference is returned to
customers. To the extent the change is less than the index range, the utility
benefits by one-half of the difference through future rate adjustments. In
fiscal 1999, the increase in O&M expense per customer was below the index range;
as a result the utility benefited by $0.7 million. Under RSE as extended, a $9.1
million, $4.5 million and a $6.6 million annual increase in revenue became
effective December 1, 2000, 1999 and 1998, respectively and a $2.5 million
annual decrease in revenue effective July 1, 1998.

Alagasco calculates a temperature adjustment to customers' monthly bills to
remove the effect of departures from normal temperature on Alagasco's earnings.
The calculation is performed monthly, and the adjustments to customers' bills
are made in the same billing cycle the weather variation occurs. Substantially
all the customers to whom the temperature adjustment applies are residential,
small commercial and small industrial. Alagasco's rate schedules for natural gas
distribution charges contain a Gas Supply Adjustment rider, established in 1993,
which permits the pass-through to customers of changes in the cost of gas
supply.

The APSC approved an Enhanced Stability Reserve (ESR), beginning fiscal year
1998, to which Alagasco may charge the full amount of: (1) extraordinary O&M
expenses resulting from force majeure events such as storms, severe weather, and
outages, when one or a combination of two such events results in more than
$200,000 of additional O&M expense during a fiscal year; or (2) individual
industrial and commercial customer revenue losses that exceed $250,000 during
the fiscal year, if such losses cause Alagasco's return on equity to fall below
13.15 percent. The APSC approved the reserve on October 6, 1998, in the amount
of $3.9 million; the maximum approved funding level of the ESR is $4 million.
Following a year in which a charge against the ESR is made, the APSC provides
for accretions to the ESR of no more than $40,000 monthly until the maximum
funding level is achieved.

In accordance with APSC-directed regulatory accounting procedures, Alagasco in
1989 began returning to customers excess utility deferred taxes which resulted
from a reduction in the federal statutory tax rate from 46 percent to 34 percent
using the average rate assumption method. This method provides for the return to
ratepayers of excess deferred taxes over the lives of the related assets. In
1993 those excess taxes were reduced as a result of a federal tax rate increase
from 34 percent to 35 percent. Remaining excess utility deferred taxes are being
returned to ratepayers over approximately 10 years. At September 30, 2000 and
1999, a regulatory liability related to income taxes of $1.4 million and $2.1
million, respectively, was included in the financial statements.

As of November 1, 1998, the Company offered a Voluntary Early Retirement Program
to certain eligible employees. The APSC has allowed these costs to be amortized
over a three-year period. At September 30, 2000 and 1999, a regulatory asset of
$1.2 million and $2.4 million, respectively, for costs associated with the early
retirement program was included in the financial statements.

The excess of total acquisition costs over book value of net assets of acquired
municipal gas distribution systems is included in utility plant and is being
amortized on a straight-line basis over approximately 23 years. At September 30,
2000 and 1999, the net acquisition adjustment was $13.4 million and $14.4
million, respectively.


                                       30
<PAGE>   32



3.       LONG-TERM DEBT AND NOTES PAYABLE


Long-term debt of Alagasco consisted of the following:


<TABLE>
<CAPTION>
==============================================================================================
As of September 30, (in thousands)                                       2000          1999
==============================================================================================
<S>                                                                     <C>           <C>
Medium-term Notes, interest ranging from 5.80% to 7.97%, for notes
   redeemable December 15, 2000, to September 23, 2026                  $119,650      $119,650
Less amounts due within one year                                           4,650            --
----------------------------------------------------------------------------------------------
  Total                                                                 $115,000      $119,650
==============================================================================================
</TABLE>



The aggregate maturities of Alagasco long-term debt for the next five years are
as follows:

<TABLE>
<CAPTION>
================================================================================
                    Years ending September 30, (in thousands)
================================================================================
      2001             2002               2003             2004           2005
--------------------------------------------------------------------------------
    <S>              <C>                <C>             <C>             <C>
    $ 4,650          $ 5,000            $ 5,000         $ 10,000        $ 10,000
================================================================================
</TABLE>


Energen and Alagasco have short-term credit lines and other credit facilities of
$249 million available as of September 30, 2000, for working capital needs;
Alagasco has been authorized to borrow up to $70 million of the available credit
lines by the APSC. The following is a summary of information relating to notes
payable to banks:


<TABLE>
<CAPTION>
=============================================================================================
As of September 30, (in thousands)                         2000          1999          1998
=============================================================================================
<S>                                                      <C>           <C>           <C>
Alagasco outstanding                                     $ 20,500      $     --      $ 15,000
Energen outstanding                                       147,500       238,000       138,000
---------------------------------------------------------------------------------------------
Notes payable to banks                                    168,000       238,000       153,000
Available for borrowings                                   81,000        11,000        75,000
---------------------------------------------------------------------------------------------
  Total                                                  $249,000      $249,000      $228,000
=============================================================================================

Alagasco maximum amount outstanding at any month-end     $ 20,500      $ 35,000      $ 36,000
Alagasco average daily amount outstanding                $  1,169      $  9,140      $ 13,225
Alagasco weighted average interest rates based on:
  Average daily amount outstanding                           6.93%         5.48%         5.94%
  Amount outstanding at year-end                             6.98%           --          5.75%
=============================================================================================
</TABLE>

Total interest expense for Alagasco in 2000, 1999 and 1998 was $9,870,000,
$10,366,000 and $10,221,000, respectively.

4.       INCOME TAXES


The components of income taxes consisted of the following:


<TABLE>
<CAPTION>
=========================================================================================
For the years ended September 30, (in thousands)       2000          1999          1998
=========================================================================================
<S>                                                  <C>           <C>           <C>
Taxes estimated to be payable currently:
    Federal                                          $ 15,225      $ 14,331      $ 15,306
    State                                               1,486         1,417         1,495
-----------------------------------------------------------------------------------------
      Total current                                    16,711        15,748        16,801
-----------------------------------------------------------------------------------------
Taxes deferred:
    Federal                                            (2,215)       (2,395)       (4,962)
    State                                                (172)         (190)         (439)
-----------------------------------------------------------------------------------------
      Total deferred                                   (2,387)       (2,585)       (5,401)
-----------------------------------------------------------------------------------------
Total income tax expense                             $ 14,324      $ 13,163      $ 11,400
=========================================================================================
</TABLE>


                                       31
<PAGE>   33




Temporary differences and carryforwards which gave rise to a significant portion
of deferred tax assets and liabilities for 2000 and 1999 are as follows:

<TABLE>
<CAPTION>
===========================================================================================
As of September 30, (in thousands)                2000                      1999
===========================================================================================
                                           CURRENT     NONCURRENT    Current     Noncurrent
                                           ----------------------    ----------------------
<S>                                        <C>         <C>           <C>         <C>
Deferred tax assets:
  Deferred investment tax credits          $    --     $    526      $    --     $    683
  Regulatory liabilities                        --          507           --          784
  Enhanced stability reserve                 1,478           --        1,452           --
  Unbilled revenue                           1,849           --        1,764           --
  Insurance and accruals                     3,170           --        3,146           --
  Inventories                                1,303           --          816           --
  Allowance for uncollectible accounts       2,193           --        1,684           --
  Pension and other costs                    1,147           --        1,587           --
  Other, net                                 1,418           68        1,698          118
------------------------------------------------------------------------------------------
  Subtotal                                  12,558        1,101       12,147        1,585
  Valuation allowance                           --           --           --           --
------------------------------------------------------------------------------------------
     Total deferred tax assets              12,558        1,101       12,147        1,585
------------------------------------------------------------------------------------------
Deferred tax liabilities:
  Depreciation and basis differences            --       17,039           --       18,274
  Other, net                                   198           --          526           --
------------------------------------------------------------------------------------------
     Total deferred tax liabilities            198       17,039          526       18,274
------------------------------------------------------------------------------------------
Net deferred tax assets (liabilities)      $12,360     $(15,938)     $11,621     $(16,689)
==========================================================================================
</TABLE>

No valuation allowance with respect to deferred taxes is deemed necessary, as
Alagasco anticipates generating adequate future taxable income to realize the
benefits of all deferred tax assets on Alagasco's balance sheet.

Total income tax expense differed from the amount which would have been provided
by applying the statutory federal income tax rate to earnings before taxes as
illustrated below:

<TABLE>
<CAPTION>
================================================================================================
For the years ended September 30, (in thousands)               2000          1999          1998
================================================================================================
<S>                                                         <C>           <C>           <C>
Income tax expense at statutory federal income tax rate     $ 14,226      $ 12,761      $ 11,195
Increase (decrease) resulting from:
  Deferred investment tax credits                               (448)         (448)         (469)
  State income taxes, net of federal income tax benefit          874           784           688
  Other, net                                                    (328)           66           (14)
------------------------------------------------------------------------------------------------
Total income tax expense                                    $ 14,324      $ 13,163      $ 11,400
================================================================================================
</TABLE>

There were no tax-related balances due to affiliates at September 30, 2000 or
1999. Alagasco has evaluated its tax position and believes the financial
statements properly reflect the income tax matters of the company.

5.       EMPLOYEE BENEFIT PLANS


All information presented concerning retirement income and other benefit plans
includes other affiliates of Energen as well as Alagasco.

The Company has two defined benefit non-contributory pension plans: Plan A which
covers a majority of the employees and Plan B which covers employees under
certain labor union agreements. Benefits are based on years of service and final
earnings. The Company's policy is to use the projected unit credit actuarial
method for funding and financial reporting purposes.


                                       32
<PAGE>   34


The status of the plans was as follows:


<TABLE>
<CAPTION>
====================================================================================================================
As of June 30, (in thousands)                                      PLAN A                            PLAN B
====================================================================================================================
                                                           2000              1999           2000              1999
                                                         --------------------------       --------------------------
<S>                                                      <C>               <C>            <C>                <C>
Projected benefit obligation:
Balance at beginning of year                             $ 73,841          $ 88,281       $ 18,227           $18,898
Service cost                                                1,988             2,653            265               299
Interest cost                                               5,573             6,193          1,361             1,338
Plan amendments                                                --                --             --               843
Actuarial loss (gain)                                      (2,642)           (8,205)          (487)           (1,803)
Special termination benefits                                   --             1,487             --                --
Benefits paid                                              (7,066)          (16,568)        (2,364)           (1,348)
--------------------------------------------------------------------------------------------------------------------
Balance at end of year                                     71,694            73,841         17,002            18,227
--------------------------------------------------------------------------------------------------------------------
Plan assets:
Fair value of plan assets at beginning of year             92,575            90,661         24,043            23,081
Actual return on plan assets                               10,972            18,482          1,882             2,310
Benefits paid                                              (7,066)          (16,568)        (2,364)           (1,348)
--------------------------------------------------------------------------------------------------------------------
Fair value of plan assets at end of year                   96,481            92,575         23,561            24,043
--------------------------------------------------------------------------------------------------------------------
Amounts recognized in the consolidated balance sheets:
Funded status of plan                                      24,787            18,734          6,559             5,816
Unrecognized actuarial loss (gain)                        (32,238)          (23,897)        (6,458)           (5,621)
Unrecognized prior service cost                             2,555             2,790          1,163             1,398
Unrecognized net transition obligation (asset)             (1,069)           (1,877)           114               170
--------------------------------------------------------------------------------------------------------------------
Accrued pension asset (liability)                        $ (5,965)         $ (4,250)      $  1,378           $ 1,763
====================================================================================================================
</TABLE>


The components of net pension expense were:


<TABLE>
<CAPTION>
=====================================================================================================================
For the years ended September 30, (in thousands)           PLAN A                                  PLAN B
=====================================================================================================================
                                                2000         1999         1998         2000         1999         1998
                                                -------------------------=----      ---------------------------------
<S>                                          <C>          <C>          <C>          <C>          <C>          <C>
Components of net periodic benefit cost:
Service cost                                 $ 1,988      $ 2,653      $ 2,386      $   265      $   299      $   224
Interest cost                                  5,573        6,193        5,842        1,361        1,338        1,261
Expected return on assets                     (5,566)      (5,938)      (5,709)      (1,577)      (1,510)      (1,346)
Prior service cost amortization                  235          235            5          235          235          207
Transition amortization                         (808)        (808)        (808)          57           57           57
---------------------------------------------------------------------------------------------------------------------
Net periodic expense                         $ 1,422      $ 2,335      $ 1,716      $   341      $   419      $   403
=====================================================================================================================
</TABLE>

<TABLE>
<CAPTION>
================================================================================================================
As of September 30,                                                 PLAN A                         PLAN B
================================================================================================================
                                                             2000            1999           2000            1999
                                                             --------------------           --------------------
<S>                                                          <C>            <C>             <C>             <C>
Weighted average rate assumptions
 in pension actuarial calculations:
Discount rate                                                8.00%          7.75%           8.00%           7.75%
Expected return on plan assets                               8.25%          8.25%           8.25%           8.25%
Rate of compensation  increase                               5.50%          5.25%             --              --
================================================================================================================
</TABLE>


The Company has supplemental retirement plans with certain key executives
providing for payments on retirement, termination, death or disability. Expense
under these agreements for 2000, 1999 and 1998 was $372,000, $(75,000), and
$(54,000), respectively. At June 30, 2000 and 1999, the accumulated
post-retirement benefit obligation related to these agreements was $3,204,000
and $2,620,000, respectively, and the projected benefit


                                       33
<PAGE>   35

obligation was $10,356,000 and $7,189,000, respectively. A prepaid
post-retirement benefit asset of $566,000 and $844,000 was recorded at June 30,
2000 and 1999, respectively.

In addition to providing pension benefits, the Company provides certain
post-retirement health care and life insurance benefits. Substantially all of
the Company's employees may become eligible for such benefits if they reach
normal retirement age while working for the Company. The projected unit credit
actuarial method was used to determine the normal cost and actuarial liability.

The status of the post-retirement benefit programs was as follows:


<TABLE>
<CAPTION>
==================================================================================================================
As of June 30, (in thousands)                               SALARIED EMPLOYEES                   UNION EMPLOYEES
==================================================================================================================
                                                           2000           1999                2000            1999
                                                           -------------------               ---------------------
<S>                                                   <C>             <C>              <C>             <C>
Projected post-retirement benefit obligation:
Balance at beginning of year                          $    29,144     $   29,312       $    37,423     $    37,751
Service cost                                                1,092          1,464             1,876           2,039
Interest cost                                               2,203          2,013             2,852           2,599
Actuarial loss (gain)                                      (1,146)        (2,530)           (1,635)         (3,709)
Special termination benefits                                   --            338                --              --
Benefits paid                                              (1,482)        (1,453)           (1,225)         (1,257)
-------------------------------------------------------------------------------------------------------------------
Balance at end of year                                     29,811         29,144            39,291          37,423
-------------------------------------------------------------------------------------------------------------------
Plan assets:
Fair value of plan assets at beginning of year             35,494         30,476            26,702          23,081
Actuarial return on plan assets                             4,186          4,896             3,928           2,468
Company contribution                                        2,806          1,575             6,005           2,410
Benefits paid                                              (1,482)        (1,453)           (1,225)         (1,257)
-------------------------------------------------------------------------------------------------------------------
Balance at end of year                                     41,004         35,494            35,410          26,702
-------------------------------------------------------------------------------------------------------------------
Amounts recognized in the consolidated balance sheets:
Funded status of plan                                      11,193          6,350            (3,881)        (10,721)
Unrecognized actuarial loss (gain)                        (19,435)       (16,468)          (11,274)         (7,266)
Unrecognized net transition obligation                      9,395         10,118            16,702          17,987
-------------------------------------------------------------------------------------------------------------------
Accrued post-retirement asset                         $     1,153     $       --       $     1,547     $        --
===================================================================================================================
</TABLE>

Net periodic post-retirement benefit expense included the following:

<TABLE>
<CAPTION>
============================================================================================================================
For the years ended September 30, (in thousands)            SALARIED EMPLOYEES                     UNION EMPLOYEES
============================================================================================================================
                                                        2000        1999        1998          2000        1999         1998
                                                      ----------------------------------    --------------------------------
<S>                                                   <C>         <C>         <C>           <C>         <C>          <C>
Components of net periodic benefit cost:
Service cost                                          $ 1,092     $ 1,464     $   967       $ 1,876     $ 2,039     $ 1,314
Interest cost                                           2,203       2,013       2,049         2,852       2,599       2,612
Expected return on assets                              (1,721)     (1,448)     (1,189)       (1,292)     (1,156)       (737)
Actuarial loss (gain)                                  (1,029)       (590)       (510)         (271)       (129)       (107)
Transition amortization                                   723         723         723         1,285       1,285       1,285
----------------------------------------------------------------------------------------------------------------------------
Net periodic expense                                  $ 1,268     $ 2,162     $ 2,040       $ 4,450      $ 4,638     $ 4,367
============================================================================================================================
</TABLE>


                                       34
<PAGE>   36

<TABLE>
<CAPTION>
==================================================================================================================
As of September 30,                                           SALARIED EMPLOYEES               UNION EMPLOYEES
==================================================================================================================
                                                             2000           1999             2000           1999
                                                             -------------------             -------------------
<S>                                                          <C>            <C>             <C>             <C>
Weighted average rate assumptions
  in post-retirement actuarial calculations:
Discount rate                                                8.00%          7.75%           8.00%           7.75%
Expected return on plan assets                               8.25%          8.25%           8.25%           8.25%
Rate of compensation increase                                5.50%          5.25%             --              --
Health care cost trend rate                                  7.50%          7.50%           7.50%           7.50%
==================================================================================================================
</TABLE>

The weighted average health care cost trend rate used in determining the
accumulated post-retirement benefit obligation has a significant effect on the
amounts reported. For example, with respect to salaried employees, increasing
the weighted average health care cost trend rate by 1 percentage point would
increase the accumulated post-retirement benefit obligation by $811,000 and the
net periodic post-retirement benefit cost by $31,000. For union employees,
increasing the weighted average health care cost trend rate by 1 percentage
point would increase the accumulated post-retirement benefit obligation by
$2,880,000 and the net periodic post-retirement benefit cost by $318,000.

For both defined benefit plans and other post-retirement plans, certain
financial assumptions are used in determining the Company's projected benefit
obligation. These assumptions are examined periodically by the Company, and any
required changes are reflected in the subsequent determination of projected
benefit obligations.

The Company has a long-term disability plan covering most salaried employees.
The Company had no expense for the year ended September 30, 2000. Expense for
the years ended September 30, 1999 and 1998 was $177,000 and $173,000,
respectively.

6.       CAPITAL STOCK

Alagasco's authorized common stock consists of 3 million, $0.01 par value common
shares. At September 30, 2000 and 1999, 1,972,052 shares were issued and
outstanding. Alagasco is authorized to issue 120,000 shares of preferred stock
par value $0.01 per share, in one or more series. There are no preferred shares
currently outstanding.

7.       COMMITMENTS AND CONTINGENCIES

CONTRACTS AND AGREEMENTS: Alagasco has various firm gas supply and firm gas
transportation contracts which expire at various dates through the year 2008.
These contracts typically contain minimum demand charge obligations on the part
of Alagasco.

ENVIRONMENTAL MATTERS: Alagasco is in the chain of title of eight former
manufactured gas plant sites, of which it still owns four, and five manufactured
gas distribution sites, of which it still owns one. An investigation of the
sites does not indicate the present need for remediation activities. Management
expects that, should remediation of any such sites be required in the future,
Alagasco's share, if any, of such costs will not affect materially the results
of operations or financial condition of Alagasco.

LEGAL MATTERS: Alagasco is, from time to time, party to various pending or
threatened legal proceedings. Certain of these lawsuits include claims for
punitive damages in addition to other specified relief. Based upon information
presently available, and in light of available legal and other defenses,
contingent liabilities arising from threatened and pending litigation are not
considered material in relation to the financial position of Alagasco. It should
be noted, however, that Alagasco conducts business in Alabama and other
jurisdictions in which the magnitude and frequency of punitive damage awards
bear little or no relation to culpability or actual damages thus making it
increasingly difficult to predict litigation results. Various legal proceedings
arising in the normal course of business are currently in progress, and Alagasco
has accrued a provision for estimated costs.


                                       35
<PAGE>   37

LEASE OBLIGATIONS: In January 1999, Alagasco closed on a sale-leaseback of the
Company's new headquarters building. The proceeds from the sale approximated the
investment in the facility. The building is being leased from the purchaser over
a 25 year lease term and the related lease is accounted for as an operating
lease. Total payments related to leases included as operating expense, inclusive
of the sale-leaseback, were $2,209,000, $2,079,000 and $2,292,000 in 2000, 1999
and 1998, respectively. Minimum future rental payments required after 2000 under
leases with initial or remaining noncancelable lease terms in excess of one year
are as follows:

<TABLE>
<CAPTION>
===================================================================================================
                    Years ending September 30, (in thousands)
===================================================================================================
         2001           2002           2003           2004          2005       2006 AND THEREAFTER
---------------------------------------------------------------------------------------------------
       <S>            <C>            <C>            <C>           <C>          <C>
       $ 2,186        $ 2,142        $ 2,111        $ 2,014       $ 1,660            $ 25,218
===================================================================================================
</TABLE>

8.       SUPPLEMENTAL CASH FLOW INFORMATION

Supplemental information concerning cash flow activities is as follows:


<TABLE>
<CAPTION>
==============================================================================================
For the years ended September 30, (in thousands)         2000            1999          1998
==============================================================================================
<S>                                                   <C>            <C>            <C>
Interest paid, net of amount capitalized              $    9,787     $  10,539      $  11,256
Income taxes paid                                     $   15,833     $  16,342      $  16,253
Noncash investing activities:
  Capitalized depreciation                            $      217     $     265      $     187
  Allowance for funds used during construction        $    1,172     $     374      $     400
==============================================================================================
</TABLE>

9.       FINANCIAL INSTRUMENTS AND RISK MANAGEMENT

FINANCIAL INSTRUMENTS: The fair value of cash and cash equivalents, trade
receivables (net of allowance), and short-term debt approximates fair value due
to the short maturity of the instruments. The fair value of fixed-rate long-term
debt, including the current portion, with a carrying value of $119,650,000,
would be $116,376,000 at September 30, 2000. The fair value was based on the
market value of debt with similar maturities and with interest rates currently
trading in the marketplace.

Alagasco has entered into an agreement with a financial institution whereby it
can sell on an ongoing basis, with recourse, certain installment receivables
related to its merchandising program up to a maximum of $20 million. During
2000, 1999 and 1998, Alagasco sold $6,879,000, $6,391,000 and $8,100,000,
respectively, of installment receivables. At September 30, 2000 and 1999, the
balance of these installment receivables was $15,280,000 and $15,690,000,
respectively. Receivables sold under this agreement are considered financial
instruments with off-balance sheet risk. Alagasco's exposure to credit loss in
the event of non-performance by customers is represented by the balance of
installment receivables.

CONCENTRATION OF CREDIT RISK: Natural gas distribution operating revenues and
related accounts receivable are generated from state-regulated utility natural
gas sales and transportation to approximately 470,000 residential, commercial
and industrial customers located in central and north Alabama. A change in
economic conditions may affect the ability of customers to meet their
obligations; however, Alagasco believes that its provision for possible losses
on uncollectible accounts receivable is adequate for its credit loss exposure.

10.      RECENT PRONOUNCEMENTS OF THE FASB


In June 1998, the FASB issued SFAS No. 133, (subsequently amended by SFAS Nos.
137 and 138), which established new accounting and reporting standards for
derivative instruments. The Company is required to adopt this statement on
October 1, 2000. This statement requires the Company to recognize all
derivatives as either assets or liabilities on the balance sheet and measure the
effectiveness of the hedges, or the degree that the gain(loss) for the hedging
instrument offsets the loss(gain) on the hedged item, at fair value each
reporting period. The effective portion of the gain or loss on the derivative
instrument will be recognized in other comprehensive income as a component of
equity until the hedged item is recognized in earnings. The ineffective portion
of the derivative's


                                       36
<PAGE>   38

change in fair value is required to be recognized in earnings immediately. The
impact of SFAS No. 133 at implementation had no impact on the results of
operation and financial position for Alagasco.

11.      SUMMARIZED QUARTERLY FINANCIAL DATA (UNAUDITED)

The following data summarize quarterly operating results. Alagasco's business is
seasonal in character and influenced by weather conditions.

<TABLE>
<CAPTION>
==============================================================================================================
Fiscal year 2000 quarters (in thousands)                   First        Second           Third        Fourth
==============================================================================================================
<S>                                                      <C>          <C>            <C>            <C>
Operating revenues                                       $   85,426   $  158,548     $  69,111      $  53,076
Operating income (loss)                                  $    6,890   $   28,283     $   2,935      $  (3,369)
Net income (loss)                                        $    4,620   $   26,055     $   1,116      $  (5,469)
==============================================================================================================

Fiscal year 1999 quarters (in thousands)
==============================================================================================================
Operating revenues                                       $   71,557   $  144,692     $  63,296      $  46,009
Operating income (loss)                                  $    5,579   $   28,158     $   2,613      $  (2,948)
Net income (loss)                                        $    2,855   $   25,198     $     507      $  (5,263)
==============================================================================================================
</TABLE>

12.      TRANSACTIONS WITH RELATED PARTIES


Alagasco purchased natural gas from affiliates amounting to $3,662,000,
$3,232,000 and $4,142,000, in 2000, 1999 and 1998, respectively. These amounts
are included in gas purchased for resale. Alagasco had net payables to
affiliates of $1,156,000 at September 30, 2000, net receivables from affiliates
of $20,654,000 at September 30, 1999 and net payables to affiliates of
$2,738,000 at September 30, 1998.


                                       37
<PAGE>   39


REPORT OF INDEPENDENT ACCOUNTANTS ON FINANCIAL STATEMENT SCHEDULE

TO THE BOARD OF DIRECTORS OF ENERGEN CORPORATION:

Our audits of the consolidated financial statements referred to in our report
dated October 25, 2000, appearing in the 2000 Annual Report to Shareholders of
Energen Corporation (which report and consolidated financial statements are
incorporated by reference in this Annual Report on Form 10-K) also included an
audit of the financial statement schedule listed in Part IV, Item 14(a)(2) of
this Form 10-K. In our opinion, the financial statement schedule presents
fairly, in all material respects, the information set forth therein when read in
conjunction with the related consolidated financial statements.



PricewaterhouseCoopers LLP
Birmingham, Alabama
October 25, 2000


                                       38
<PAGE>   40


SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS
ENERGEN CORPORATION AND SUBSIDIARIES



<TABLE>
<CAPTION>
===============================================================================

YEARS ENDED SEPTEMBER 30, (IN THOUSANDS)         2000         1999         1998
===============================================================================
<S>                                           <C>          <C>          <C>

ALLOWANCE FOR DOUBTFUL ACCOUNTS
BALANCE AT BEGINNING OF YEAR                  $ 5,598      $ 3,547      $ 3,185
-------------------------------------------------------------------------------

   Additions:
     Charged to income                          4,287        6,121        3,472
     Recoveries and adjustments                  (276)        (244)        (215)
-------------------------------------------------------------------------------

        Net additions                           4,011        5,877        3,257
-------------------------------------------------------------------------------

  Less uncollectible accounts written off      (2,928)      (3,826)      (2,895)
-------------------------------------------------------------------------------

BALANCE AT END OF YEAR                        $ 6,681      $ 5,598      $ 3,547
===============================================================================
</TABLE>


                                       39
<PAGE>   41


SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS
ALABAMA GAS CORPORATION



<TABLE>
<CAPTION>
==============================================================================

YEARS ENDED SEPTEMBER 30, (IN THOUSANDS)        2000         1999         1998
==============================================================================

<S>                                          <C>          <C>          <C>
ALLOWANCE FOR DOUBTFUL ACCOUNTS
BALANCE AT BEGINNING OF YEAR                 $ 4,532      $ 3,482      $ 3,156
------------------------------------------------------------------------------

  Additions:
    Charged to income                          4,275        5,105        3,430
    Recoveries and adjustments                  (276)        (244)        (215)
------------------------------------------------------------------------------

       Net additions                           3,999        4,861        3,215
------------------------------------------------------------------------------

 Less uncollectible accounts written off      (2,731)      (3,811)      (2,889)
------------------------------------------------------------------------------


BALANCE AT END OF YEAR                       $ 5,800      $ 4,532      $ 3,482
==============================================================================
</TABLE>


                                       40