<PAGE>


                                  UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                              WASHINGTON, DC 20549


                                    FORM 10-Q

[X]  QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE
     ACT OF 1934

     For Quarterly Period 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 file number 1-2967.

                             UNION ELECTRIC COMPANY
             (Exact name of registrant as specified in its charter)

            Missouri                                            43-0559760
(State or other jurisdiction of                              (I.R.S. Employer
incorporation or organization)                               Identification No.)


                 1901 Chouteau Avenue, St. Louis, Missouri 63103
              (Address of principal executive offices and Zip Code)


                         Registrant's telephone number,
                       including area code: (314) 621-3222


     Indicate  by check mark  whether the  registrant  (1) has filed all reports
required to be filed by Section 13 or 15(d) of the  Securities  Exchange  Act of
1934  during  the  preceding  12 months  (or for such  shorter  period  that the
registrant was required to file such reports),  and (2) has been subject to such
filing requirements for the past 90 days.


                            Yes    X.     No     .
                                 -----        -----



Shares outstanding of each of registrant's classes of common stock as of October
  31, 2000:  Common  Stock,  $5 par value,  held by Ameren  Corporation  (parent
  company of Registrant) - 102,123,834


<PAGE>


                             Union Electric Company

                                      Index

                                                                       Page No.

Part I   Financial Information (Unaudited)

         Management's Discussion and Analysis                             2

         Quantitative and Qualitative Disclosures
         About Market Risk                                                6

         Balance Sheet
         - September 30, 2000 and December 31, 1999                       8

         Statement of Income
         - Three months, nine months and 12 months ended
            September 30, 2000 and 1999                                   9

         Statement of Cash Flows
         - Nine months ended September and 1999                          10

         Notes to Financial Statements                                   11


Part II  Other Information                                               14


<PAGE>


                    PART I. FINANCIAL INFORMATION (UNAUDITED)

MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF
OPERATIONS

OVERVIEW

Union Electric  Company  (AmerenUE or the  Registrant) is a subsidiary of Ameren
Corporation  (Ameren),  a holding  company  registered  under the Public Utility
Holding  Company Act of 1935  (PUHCA).  In December  1997,  AmerenUE  and CIPSCO
Incorporated  (CIPSCO)  combined to form  Ameren,  with  AmerenUE  and  CIPSCO's
subsidiaries,  Central  Illinois Public Service Company  (AmerenCIPS) and CIPSCO
Investment Company (CIC), becoming subsidiaries of Ameren (the Merger).

The following  discussion and analysis  should be read in  conjunction  with the
Notes to the  Financial  Statements  beginning on page 11, and the  Management's
Discussion and Analysis of Financial Condition and Results of Operations (MD&A),
the Audited  Financial  Statements,  and the Notes to the  Financial  Statements
appearing in the Registrant's 1999 Form 10-K.


RESULTS OF OPERATIONS

Earnings
Third  quarter 2000  earnings of $202 million  decreased $5 million  compared to
1999 third quarter  earnings.  Earnings for the nine months ended  September 30,
2000,  increased $7 million from the year ago period to $324  million.  Earnings
for the 12 months  ended  September  30, 2000 were $347  million,  a $16 million
increase from the preceding  12-month  period.  Earnings  fluctuated due to many
conditions,  primarily:  sales growth,  weather variations,  credits to electric
customers,  electric rate  reductions,  gas rate increases,  competitive  market
forces,  fluctuating operating costs (including Callaway Nuclear Plant refueling
outages), changes in interest expense, changes in income and property taxes, and
a nonrecurring charge for a targeted employee separation plan.

The  significant  items  affecting  revenues,  costs  and  earnings  during  the
three-month,  nine-month and 12-month  periods ended September 30, 2000 and 1999
are detailed on the following pages.

Electric Operations
Electric Operating Revenues     Variations for periods ended September  30, 2000
                                       from comparable prior-year periods
-----------------------------------------------------------------
(Millions of Dollars)           Three Months        Nine Months    Twelve Months
                                ------------        -----------    ------------
--------------------------------------------------------------------------------
Rate variations                $        -       $             -   $           7
Credit to customers                   (18)                  (13)            (27)
Effect of abnormal weather             (7)                  (23)            (25)
Growth and other                        8                    50              74
Interchange sales                     (16)                   67              80
--------------------------------------------------------------------------------
                               $      (33)        $           81   $         109
-------------------------------------------------------------------------------

The $33 million  decrease in third  quarter  electric  revenues  compared to the
year-ago  quarter was primarily driven by a decrease in industrial and wholesale
sales of 16 percent and 37 percent,  respectively,  offset in part by  increased
commercial sales of 9 percent. Interchange revenues declined due to lower energy
prices in the third  quarter  compared to the prior year  period.  In  addition,
revenues  declined  due to an  increase  in the  estimated  credit  to  Missouri
electric  customers (see Note 5 under Notes to Financial  Statements for further
information).

Electric  revenues  for the first  nine  months of 2000  increased  $81  million
compared to the same 1999 period.  The increase in revenues was primarily due to
a 50 percent increase in interchange sales due to strong marketing  efforts.  In
addition,  revenues increased due to increased residential and commercial sales,
by 1 percent and 7 percent, respectively.  These increases were partially offset
by a 5 percent  and 49  percent  decline  in  industrial  and  wholesale  sales,
respectively. In addition, revenues declined due to an increase in the estimated
credit to  Missouri  electric  customers  (see Note 5 under  Notes to  Financial
Statements for further information).

                                      -2-

<PAGE>

Electric  revenues for the 12 months ended September 30, 2000 and 1999 increased
$109 million compared to the prior 12-month period. The increase in revenues was
primarily due to a 35 percent  increase in interchange  sales,  coupled with a 8
percent increase in commercial sales.

Fuel and Purchased Power    Variations for periods ended September  30, 2000
                                 from comparable prior-year periods
--------------------------------------------------------------------------------
(Millions of Dollars)                  Three Months   Nine Months  Twelve Months
                                       ------------   -----------  -------------
--------------------------------------------------------------------------------
Fuel:
     Generation                         $   5         $      13        $   4
     Price                                 (7)              (16)         (10)
     Generation efficiencies and other      -                (4)          (7)
Purchased power variation                 (28)               39           81
--------------------------------------------------------------------------------
                                       $  (30)         $     32           68
--------------------------------------------------------------------------------


The $30 million decrease in fuel and purchased power for the three-months  ended
September  30,  2000,  compared to the year ago period,  was driven by decreased
purchased power, coupled with lower fuel and purchased power prices.

The increase in fuel and purchased  power costs for the  nine-month and 12-month
periods ended September 30, 2000,  compared to the year ago comparable  periods,
was  primarily  due to increased  purchased  power  resulting  from higher sales
volumes, offset in part by lower fuel prices.

Gas Operations
Gas revenues for the  nine-months  ended September 30, 2000 increased $3 million
compared to the prior-year period primarily due to higher gas costs.

Gas costs for the three,  nine and 12 months ended  September 30, 2000 increased
$3 million,  $5 million and $6 million,  respectively,  compared to the year-ago
periods, primarily due to higher gas prices.

Other Operating Expenses
Other operating expense variations  reflected  recurring factors such as growth,
inflation, labor and benefit increases.

Other operations expenses for the nine-months ended September 30, 2000 increased
$12 million,  compared to the same  year-ago  period  primarily due to increased
costs  associated  with the  automated  meter  reading  roll-out  and  increased
professional  services,  partially offset by lower employee benefits,  resulting
from a change in actuarial  assumptions.  Other operations expenses decreased $8
million  for the 12  months  ended  September  30,  2000,  compared  to the same
year-ago period  primarily due to the 1998 one-time pretax charge of $18 million
for a targeted separation plan.

Maintenance  expenses for the three, nine and 12 months ended September 30, 2000
increased $4 million, $19 million and $33 million, respectively, compared to the
year-ago periods  primarily due to increased  scheduled power plant  maintenance
and tree trimming activity.

Taxes
Income  taxes  decreased  $5 million for the third  quarter due to lower  pretax
income.

Income  taxes  increased  $4 million and $2 million,  for the nine and 12 months
ended September 30, 2000, respectively, due to higher pretax income.

Other Income and Deductions
The  variation  in  miscellaneous,  net for the three,  nine and 12 months ended
September  30, 2000,  compared to the year ago periods is primarily due to prior
period write-offs of certain non-regulated investments.


                                      -3-


<PAGE>


Balance Sheet

The $70 million  increase in trade accounts  receivable and unbilled  revenue at
September  30,  2000,  compared to the  year-end,  was due  primarily  to higher
revenues in August and September 2000 compared to November and December 1999.

Changes in accounts and wages payable and other taxes accrued  resulted from the
timing of various payments to taxing authorities and suppliers.


LIQUIDITY AND CAPITAL RESOURCES

Cash provided by operating  activities  totaled $652 million for the nine months
ended September 30, 2000, compared to $639 million during the same 1999 period.

Cash flows used in  investing  activities  totaled $224 million and $260 million
for  the  nine  months  ended   September  30,  2000  and  1999,   respectively.
Construction  expenditures  for the nine months ended  September  30, 2000,  for
constructing  new  or  improving  existing  facilities  were  $230  million.  In
addition,  the  Registrant  expended $12 million for the  acquisition of nuclear
fuel. The Registrant  received  approval of Ameren's Board of Directors on April
25, 2000 to spend approximately $160 million on capital expenditures relating to
the  replacement  of  four  steam  generators  at its  Callaway  Nuclear  Plant.
Installation  is scheduled to be  completed in 2005.  The impact on  anticipated
2000 capital expenditures will be insignificant.

Cash flows used in financing activities totaled $367 million for the nine months
ended September 30, 2000,  compared to $149 million during the same 1999 period.
The  Registrant's  principal  financing  activities for the period  included the
issuance and redemption of long-term debt and the payment of dividends.

The Registrant  plans to continue  utilizing  short-term  debt to support normal
operations and other temporary requirements. The Registrant is authorized by the
Securities  and  Exchange  Commission  under  PUHCA to have up to $1  billion of
short-term  unsecured debt instruments  outstanding at any one time.  Short-term
borrowings  consist of bank loans and  commercial  paper  (maturities  generally
within 1 to 45 days).  At September 30, 2000,  the Registrant had committed bank
lines of credit  aggregating $150 million (all of which was unused and available
at such date)  which  make  available  interim  financing  at  various  rates of
interest based on LIBOR,  the bank certificate of deposit rate or other options.
The lines of credit are renewable annually at various dates throughout the year.
At September 30, 2000, the Registrant had no outstanding short-term borrowings.

The  Registrant  also has a bank  credit  agreement  due 2002 which  permits the
borrowing  of up to $300 million on a long-term  basis,  all of which was unused
and available at September 30, 2000. In addition, the Registrant has the ability
to borrow up to approximately  $525 million from Ameren or AmerenCIPS  through a
regulated  money pool  agreement.  The regulated  money pool was  established to
coordinate  and  provide  for  certain   short-term  cash  and  working  capital
requirements and is administered by Ameren Services Company,  another subsidiary
of Ameren.  Interest is calculated at varying rates of interest depending on the
composition  of internal and external  funds in the regulated  money pool. As of
September 30, 2000, $59 million was available through the regulated money pool.

Additionally,  the  Registrant  has a  lease  agreement  that  provides  for the
financing of nuclear fuel. At September 30, 2000,  the maximum amount that could
be  financed  under the  agreement  was $120  million.  Cash  used in  financing
activities for the nine months ended  September 30, 2000,  included  redemptions
under  the  lease for  nuclear  fuel of $8  million,  offset  by $7  million  of
issuances. At September 30, 2000, $116 million was financed under the lease.

The Registrant,  in the ordinary course of business,  explores  opportunities to
reduce its costs in order to remain competitive in the marketplace.  Areas where
the Registrant  focuses its review include,  but are not limited to, labor costs
and fuel supply costs. In the labor area, the Registrant has reached  agreements
with some of the Registrant's  collective  bargaining units which will permit it
to  manage  its  labor  costs  and  practices  effectively  in the  future.  The
Registrant  also explores  alternatives  to  effectively  manage the size of its
workforce. These alternatives include utilizing hiring freezes,  outsourcing and
offering employee separation  packages.  In the fuel supply area, the Registrant
explores  alternatives  to  effectively  manage its overall  fuel  costs.  These
alternatives  include  diversifying

                                      -4-

<PAGE>

fuel  sources  for use at the  Registrant's
fossil plants, as well as restructuring or terminating  existing  contracts with
suppliers.

Certain  of  these  cost  reduction  alternatives  could  result  in  additional
investments  being  made at the  Registrant's  power  plants in order to utilize
different  types of coal,  or could  require  nonrecurring  payments of employee
separation  benefits or  nonrecurring  payments to  restructure  or terminate an
existing fuel  contract  with a supplier.  Management is unable to predict which
(if any),  and to what  extent,  these  alternatives  to reduce its overall cost
structure  will be executed.  Management  is unable to  determine  the impact of
these  actions  on  the  Registrant's  future  financial  position,  results  of
operations or liquidity.


RATE MATTERS

On October 17, 2000, the Missouri Public Service  Commission  (MoPSC) approved a
$4.2 million annual rate increase for natural gas service in AmerenUE's Missouri
jurisdiction. The rate increase became effective on November 1, 2000.

With  respect  to the  Registrant's  current  electric  three-year  experimental
alternative  regulation plan, in November 2000, the MoPSC approved a stipulation
and agreement of the parties  regarding the credit to be paid by the  Registrant
to its Missouri electric  customers for the plan year ended June 30, 1999. Based
on the provisions of the  stipulation  and  agreement,  the credit to be paid to
electric  customers for the plan year ended June 30, 1999 will  approximate  $22
million.

See Note 5 under Notes to Financial  Statements  for further  discussion of Rate
Matters.

In September 2000, the Registrant and its affiliate, AmerenCIPS, filed a request
with the Illinois  Commerce  Commission (ICC) seeking  authorization to transfer
its  Illinois-based  electric and natural gas  business  and its  Illinois-based
distribution   and  transmission   assets  and  personnel  to  AmerenCIPS.   The
distribution and transmission assets and related liabilities will be transferred
from AmerenUE to AmerenCIPS at historical net book value of  approximately  $101
million.  In connection with this transaction,  the Registrant will receive from
AmerenCIPS an intercompany  note receivable of  approximately  $50 million.  The
balance of the assets will be transferred to AmerenCIPS in the form of a capital
contribution. In October 2000, the Registrant filed a request with the MoPSC for
approval of this  transfer.  The transfer is also subject to regulatory  filings
and  approvals  of the  Federal  Energy  Regulatory  Commission  (FERC)  and the
Securities Exchange Commission.

ELECTRIC INDUSTRY RESTRUCTURING

Certain states are considering  proposals or have adopted  legislation that will
promote  competition  at the retail  level.  In December  1997,  the Governor of
Illinois signed the Electric Service Customer Choice and Rate Relief Law of 1997
(the Illinois Law)  providing for electric  utility  restructuring  in Illinois.
This  legislation  introduces  competition into the supply of electric energy in
Illinois.

The Illinois Law, among other things,  requires the  phasing-in  through 2002 of
retail direct access, which allows customers to choose their electric generation
supplier.  The phase-in of retail direct  access began on October 1, 1999,  with
large  commercial and industrial  customers  principally  comprising the initial
group.  The  customers in this group  represent  approximately  6 percent of the
Registrant's  total sales. As of September 30, 2000, the impact of retail direct
access  on the  Registrant's  financial  condition,  results  of  operations  or
liquidity was immaterial.  Retail direct access will be offered to the remaining
commercial  and  industrial  customers on December  31, 2000 and to  residential
customers on May 1, 2002.

MIDWEST ISO

On November 9, 2000, the Registrant announced its intention to withdraw from the
Midwest  Independent System Operator (Midwest ISO) and to become a member of the
Alliance  Regional  Transmission   Organization   (Alliance  RTO),  pending  the
necessary regulatory approvals.  The Alliance RTO, including its rate structure,
is still  subject  to  approval  by the FERC.  Accordingly,  the  Registrant  is
currently  unable to determine the impact that operation of the Alliance RTO, or
the  withdrawal  from the Midwest  ISO,  will have on its  financial  condition,
results of operations or liquidity.

                                      -5-


<PAGE>

QUANTITATIVE AND QUALITATIVE DISCLOSURES ABOUT MARKET RISK

Market risk  represents the risk of changes in value of a financial  instrument,
derivative  or  non-derivative,  caused by  fluctuations  in interest  rates and
equity prices.  The following  discussion of the  Registrant's  risk  management
activities  includes   "forward-looking"   statements  that  involve  risks  and
uncertainties.  Actual results could differ  materially  from those projected in
the  "forward-looking"  statements.  The  Registrant  handles  market  risks  in
accordance with  established  policies,  which may include entering into various
derivative  transactions.  In the normal course of business, the Registrant also
faces  risks  that are  either  non-financial  or  non-quantifiable.  Such risks
principally  include  business,  legal,  operational and credit risk and are not
represented in the following analysis.

Interest Rate Risk
The  Registrant  is exposed to market risk  through  changes in  interest  rates
through its issuance of both  long-term and  short-term  variable-rate  debt and
commercial  paper.  The  Registrant   manages  its  interest  rate  exposure  by
controlling  the  amount  of  these   instruments  it  holds  within  its  total
capitalization  portfolio  and by  monitoring  the effects of market  changes in
interest rates.

If interest rates increase one percentage point in 2001 as compared to 2000, the
Registrant's interest expense would increase by approximately $6 million and net
income  would  decrease  by  approximately  $3  million.  This  amount  has been
determined using the assumptions that the Registrant's outstanding variable rate
debt as of September 30, 2000, continued to be outstanding  throughout 2001, and
that the average interest rates for these  instruments  increased one percentage
point over 2000. The model does not consider the effects of the reduced level of
overall economic activity that would exist in such an environment.  In the event
of a significant change in interest rates,  management would likely take actions
to further  mitigate  its  exposure to this  market  risk.  However,  due to the
uncertainty  of the  specific  actions  that  would be taken and their  possible
effects,  the  sensitivity  analysis  assumes  no  change  in  the  Registrant's
financial structure.

Commodity Price Risk
The  Registrant  is exposed to changes in market prices for natural gas and fuel
and  electricity.   With  regard  to  its  natural  gas  utility  business,  the
Registrant's  exposure to changing  market prices is in large part  mitigated by
the fact that the Registrant has Purchased Gas Adjustment Clauses (PGA) in place
in both its Missouri and Illinois  jurisdictions.  The PGA allows the Registrant
to pass on to its customers its prudently incurred costs of natural gas.

Since  the  Registrant  does not  have a  provision  similar  to the PGA for its
electric operations, the Registrant has entered into several long-term contracts
with various  suppliers to purchase coal and nuclear fuel to manage its exposure
to fuel prices. With regard to the Registrant's exposure to commodity price risk
for  purchased  power and excess  electricity  sales,  Ameren has  established a
subsidiary,  AmerenEnergy,  Inc.,  (AmerenEnergy)  whose primary  responsibility
includes  managing  market risks  associated with the changing market prices for
electricity purchased and sold on behalf of the Registrant.

AmerenEnergy  utilizes  several  techniques  to  mitigate  its  market  risk for
electricity,  including utilizing derivative financial instruments. A derivative
is a contract  whose  value is  dependent  on or derived  from the value of some
underlying  asset. The derivative  financial  instruments  that  AmerenEnergy is
allowed to utilize (which include  forward  contracts,  futures  contracts,  and
option  contracts)  are  dictated by a risk  management  policy,  which has been
reviewed with the Auditing Committee of Ameren's Board of Directors.  Compliance
with the risk  management  policy  is the  responsibility  of a risk  management
steering  committee,  consisting  of Ameren  officers  and an  independent  risk
management officer at AmerenEnergy.

As of September  30, 2000,  the fair value of derivative  financial  instruments
exposed to commodity price risk was immaterial.

Equity Price Risk

The  Registrant  maintains  trust funds,  as required by the Nuclear  Regulatory
Commission  and  Missouri  and Illinois  state laws,  to fund  certain  costs of
nuclear  decommissioning.  As of September  30, 2000,  these funds were invested

                                      -6-

<PAGE>

primarily in domestic equity securities,  fixed-rate,  fixed-income  securities,
and cash  and  cash  equivalents.  By  maintaining  a  portfolio  that  includes
long-term equity investments,  the Registrant is seeking to maximize the returns
to be  utilized  to fund  nuclear  decommissioning  costs.  However,  the equity
securities  included  in  the  Registrant's   portfolio  are  exposed  to  price
fluctuations in equity markets, and the fixed-rate,  fixed-income securities are
exposed to changes in interest  rates.  The  Registrant  actively  monitors  its
portfolio by benchmarking  the  performance of its  investments  against certain
indices and by  maintaining,  and  periodically  reviewing,  established  target
allocation  percentages  of the  assets  of its  trusts  to  various  investment
options. The Registrant's  exposure to equity price market risk is in large part
mitigated due to the fact that the  Registrant  is currently  allowed to recover
its decommissioning costs in its rates.


ACCOUNTING MATTERS

In June 1998, the Financial  Accounting  Standards Board (FASB) issued Statement
of  Financial  Accounting  Standards  (SFAS)  133,  "Accounting  for  Derivative
Instruments  and  Hedging  Activities."  SFAS  133  establishes  accounting  and
reporting  standards for derivative  instruments,  including certain  derivative
instruments embedded in other contracts, and for hedging activities and requires
recognition  of all  derivatives  as either assets or liabilities on the balance
sheet  measured  at fair  value.  In June 1999,  the FASB  issued  SFAS No. 137,
"Accounting for Derivative  Instruments and Hedging Activities - Deferral of the
Effective  Date of FASB  Statement No. 133," which delayed the effective date of
SFAS 133 to all fiscal  quarters of all fiscal years,  beginning  after June 15,
2000.  In June 2000,  the FASB  issued  SFAS No.  138,  "Accounting  for Certain
Derivative  Instruments  and Certain  Hedging  Activities  -an amendment of FASB
Statement No. 133," which amended certain accounting and reporting  standards of
SFAS 133. Management believes that adoption of SFAS 133 will not have a material
impact on the  Registrant's  financial  position or results of  operations  upon
adoption based on the derivative instruments that existed at September 30, 2000.
However, changing market conditions, and the volume of future transactions which
fall within the scope of SFAS 133, as amended,  and the interpretations from the
FASB's  Derivative   Implementation  Group  could  change  management's  current
assessment.  As a result, SFAS 133, as amended, could increase the volatility of
the  Registrant's  future  earnings  and could be material  to the  Registrant's
financial position and results of operations upon adoption.

SAFE HARBOR STATEMENT

Statements made in this Form 10-Q which are not based on historical  facts,  are
"forward-looking"  and, accordingly,  involve risks and uncertainties that could
cause actual results to differ  materially from those  discussed.  Although such
"forward-looking"  statements  have  been  made in good  faith  and are based on
reasonable assumptions,  there is no assurance that the expected results will be
achieved.  These statements include (without limitation) statements as to future
expectations,  beliefs, plans, strategies,  objectives,  events,  conditions and
financial  performance.  In connection with the "Safe Harbor"  provisions of the
Private  Securities  Litigation  Reform Act of 1995, the Registrant is providing
this cautionary  statement to identify important factors that could cause actual
results to differ materially from those anticipated.  The following factors,  in
addition to those discussed elsewhere in this report and in the Annual Report on
Form 10-K for the  fiscal  year  ended  December  31,  1999,  and in  subsequent
securities  filings,  could cause results to differ  materially  from management
expectations as suggested by such "forward-looking"  statements:  the effects of
regulatory actions;  changes in laws and other governmental  actions; the impact
on the  Registrant  of  current  regulations  related to the  phasing-in  of the
opportunity  for some  customers  to  choose  alternative  energy  suppliers  in
Illinois; the effects of increased competition in the future due to, among other
things, deregulation of certain aspects of the Registrant's business at both the
State and Federal  levels;  future market  prices for fuel and purchased  power,
electricity,  and  natural  gas,  including  the use of  financial  instruments;
average rates for electricity in the Midwest;  business and economic conditions;
interest rates;  weather  conditions;  fuel prices and availability;  generation
plant performance;  the impact of current environmental regulations on utilities
and generating  companies and the expectation  that more stringent  requirements
will be introduced over time, which could potentially have a negative  financial
effect; monetary and fiscal policies;  future wages and employee benefits costs;
and legal and administrative proceedings.

                                      -7-

<PAGE>

<TABLE>
<CAPTION>

                             UNION ELECTRIC COMPANY
                                  BALANCE SHEET
                                    UNAUDITED
                      (Thousands of Dollars, Except Shares)



                                                              September 30,  December 31,
ASSETS                                                            2000           1999
------                                                        -------------  ------------
<S>                                                              <C>          <C>
Property and plant, at original cost:
   Electric                                                      $9,400,524   $9,210,122
   Gas                                                              234,148      223,789
   Other                                                             37,139       37,156
                                                                 ----------   ----------
                                                                  9,671,811    9,471,067
   Less accumulated depreciation and amortization                 4,518,530    4,320,910
                                                                 ----------   ----------
                                                                  5,153,281    5,150,157
Construction work in progress:
   Nuclear fuel in process                                          100,975       88,830
   Other                                                             99,494       92,833
                                                                 ----------   ----------
         Total property and plant, net                            5,353,750    5,331,820
                                                                 ----------   ----------
Investments and other assets:
   Nuclear decommissioning trust fund                               194,294      186,760
   Other                                                             61,837       59,748
                                                                 ----------   ----------
         Total investments and other assets                         256,131      246,508
                                                                 ----------   ----------
Current assets:
   Cash and cash equivalents                                        178,786      117,308
   Accounts receivable - trade (less allowance for doubtful
         accounts of $7,990 and $5,308, respectively)               230,710      151,399
   Unbilled revenue                                                  69,146       78,213
   Other accounts and notes receivable                               39,503       19,803
   Intercompany notes receivable                                    158,050      165,700
   Materials and supplies, at average cost -
      Fossil fuel                                                    64,012       65,292
      Other                                                          81,317       90,921
   Other                                                             19,101       19,205
                                                                 ----------   ----------
         Total current assets                                       840,625      707,841
                                                                 ----------   ----------
Regulatory assets:
   Deferred income taxes                                            600,069      600,604
   Other                                                            149,825      156,789
                                                                 ----------   ----------
         Total regulatory assets                                    749,894      757,393
                                                                 ----------   ----------
Total Assets                                                     $7,200,400   $7,043,562
                                                                 ==========   ==========

CAPITAL AND LIABILITIES
Capitalization:
   Common stock, $5 par value, 150,000,000 shares authorized -
     102,123,834 shares outstanding                              $  510,619   $  510,619
   Other paid-in capital, principally premium on
     common stock                                                   701,896      701,896
   Retained earnings                                              1,337,505    1,221,167
                                                                 ----------   ----------
         Total common stockholder's equity                        2,550,020    2,433,682
   Preferred stock not subject to mandatory redemption              155,197      155,197
   Long-term debt                                                 1,729,845    1,882,601
                                                                 ----------   ----------
         Total capitalization                                     4,435,062    4,471,480
                                                                 ----------   ----------
Current liabilities:
   Current maturity of long-term debt                                12,653       11,423
   Accounts and wages payable                                       249,251      234,845
   Accumulated deferred income taxes                                 37,963       48,139
   Taxes accrued                                                    258,142      119,699
   Other                                                            188,731      208,373
                                                                 ----------   ----------
         Total current liabilities                                  746,740      622,479
                                                                 ----------   ----------
Accumulated deferred income taxes                                 1,309,606    1,248,721
Accumulated deferred investment tax credits                         134,337      138,665
Regulatory liability                                                150,110      154,399
Other deferred credits and liabilities                              424,545      407,818
                                                                 ----------   ----------
Total Capital and Liabilities                                    $7,200,400   $7,043,562
                                                                 ==========   ==========

See Notes to Financial Statements.

</TABLE>

                                      -8-

<PAGE>

<TABLE>
<CAPTION>

                             UNION ELECTRIC COMPANY
                               STATEMENT OF INCOME
                                    UNAUDITED
                             (Thousands of Dollars)




                                                  Three Months Ended            Nine Months Ended             Twelve Months Ended
                                                    September 30,                 September 30,                   September 30,
                                             ---------------------------  ----------------------------     ------------------------
                                                  2000           1999           2000           1999            2000         1999
                                                  ----           ----           ----           ----            ----         ----

 OPERATING REVENUES:
<S>                                          <C>            <C>            <C>            <C>              <C>          <C>
    Electric                                 $   862,691    $   895,308    $ 2,046,001    $ 1,964,871      $2,516,147   $2,407,220
    Gas                                           11,173         10,542         71,345         68,246          95,077       94,242
    Other                                           --             --             --              171            --            199
                                             -----------    -----------    -----------    -----------      ----------   ----------
       Total operating revenues                  873,864        905,850      2,117,346      2,033,288       2,611,224    2,501,661

 OPERATING EXPENSES:
    Operations
       Fuel and purchased power                  193,152        223,194        544,766        512,611        688,689        620,826
       Gas                                        10,356          7,779         42,804         38,136         59,137         52,721
       Other                                     124,644        125,041        350,037        338,193        446,300        454,562
                                             -----------    -----------    -----------    -----------    -----------    -----------
                                                 328,152        356,014        937,607        888,940      1,194,126      1,128,109
     Maintenance                                  56,057         51,887        188,717        170,127        265,725        232,562
     Depreciation and amortization                67,715         66,594        201,899        196,917        261,054        262,591
     Income taxes                                130,989        135,952        220,473        216,854        234,310        232,522
     Other taxes                                  62,826         59,696        160,737        159,564        205,714        205,493
                                             -----------    -----------    -----------    -----------    -----------    -----------
       Total operating expenses                  645,739        670,143      1,709,433      1,632,402      2,160,929      2,061,277

 OPERATING INCOME                                228,125        235,707        407,913        400,886        450,295        440,384

 OTHER INCOME AND (DEDUCTIONS):
    Allowance for equity funds used
       during construction                         1,250          1,149          4,079          6,037          5,212          7,652
    Miscellaneous, net                             4,475          1,933         10,016          4,648         17,016         11,510
                                             -----------    -----------    -----------    -----------    -----------    -----------
       Total other income and (deductions)         5,725          3,082         14,095         10,685         22,228         19,162

 INCOME BEFORE
    INTEREST CHARGES                             233,850        238,789        422,008        411,571        472,523        459,546

 INTEREST CHARGES:
    Interest                                      31,846         31,769         97,860         93,747        124,091        126,135
    Allowance for borrowed funds
       used during construction                   (2,083)        (1,707)        (6,027)        (5,315)        (7,856)        (6,694)
                                             -----------    -----------    -----------    -----------    -----------    -----------
    Net interest charges                          29,763         30,062         91,833         88,432        116,235        119,441

 NET INCOME                                      204,087        208,727        330,175        323,139        356,288        340,105

 PREFERRED STOCK DIVIDENDS                         2,204          2,204          6,613          6,613          8,817          8,817
                                             -----------    -----------    -----------    -----------    -----------    -----------

NET INCOME AFTER PREFERRED
    STOCK DIVIDENDS                          $   201,883    $   206,523    $   323,562    $   316,526    $   347,471    $   331,288
                                             ===========    ===========    ===========    ===========    ===========    ===========

See Notes to Financial Statements.

</TABLE>

                                      -9-

<PAGE>

<TABLE>
<CAPTION>

                             UNION ELECTRIC COMPANY
                             STATEMENT OF CASH FLOWS
                                    UNAUDITED
                             (Thousands of Dollars)




                                                          Nine Months Ended
                                                            September 30,
                                                          2000         1999
                                                          ----         ----
Cash Flows From Operating:
<S>                                                     <C>          <C>
   Net income                                           $330,175     $323,139
   Adjustments to reconcile net income to net cash
      provided by operating activities:
        Depreciation and amortization                    192,937      189,914
        Amortization of nuclear fuel                      27,714       30,823
        Allowance for funds used during construction     (10,106)     (11,352)
        Deferred income taxes, net                         6,913       (5,638)
        Deferred investment tax credits, net              (4,328)      (4,158)
        Changes in assets and liabilities:
           Receivables, net                              (89,944)     (99,984)
           Materials and supplies                         10,884      (14,990)
           Accounts and wages payable                     14,406
                                                                      (41,745)
           Taxes accrued                                 138,443      171,685
           Credit to customers                           (18,507)      36,597
           Other, net                                     53,842       64,650
                                                       ---------    ---------
Net cash provided by operating activities                652,429      638,941

Cash Flows From Investing:
   Construction expenditures                            (230,023)    (173,160)
   Allowance for funds used during construction           10,106       11,352
   Nuclear fuel expenditures                             (11,691)     (19,662)
   Intercompany notes receivable                           7,650      (78,800)
                                                       ---------    ---------
Net cash used in investing activities                   (223,958)    (260,270)

Cash Flows From Financing:
   Dividends on common stock                            (207,224)    (191,380)
   Dividends on preferred stock                           (6,613)      (6,613)
   Redemptions -
         Nuclear fuel lease                               (8,276)     (11,332)
         Long-term debt                                 (338,650)        --
   Issuances -
         Nuclear fuel lease                                7,270       60,045
         Long-term debt                                  186,500         --
                                                       ---------    ---------
Net cash used in financing activities                   (366,993)    (149,280)

Net change in cash and cash equivalents                   61,478      229,391
Cash and cash equivalents at beginning of year           117,308      47,337
                                                       ---------    ---------
Cash and cash equivalents at end of period             $ 178,786    $ 276,728
                                                       =========    =========

Cash paid during the periods:
   Interest (net of amount capitalized)                $  80,537    $  77,288
   Income taxes, net
                                                       $ 114,548    $ 120,186

See Notes to Financial Statements.

</TABLE>

                                      -10-

<PAGE>

UNION ELECTRIC COMPANY
NOTES TO FINANCIAL STATEMENTS (UNAUDITED)
September 30, 2000

Note 1 - Union Electric Company  (AmerenUE or the Registrant) is a subsidiary of
Ameren  Corporation  (Ameren),  which is the  parent  company  of the  following
operating  companies:  the Registrant,  Central  Illinois Public Service Company
(AmerenCIPS) and AmerenEnergy  Generating  Company, a wholly owned subsidiary of
AmerenEnergy Resources Company. Ameren is a registered holding company under the
Public Utility  Holding Company Act of 1935 (PUHCA) formed in December 1997 upon
the merger of AmerenUE and CIPSCO Incorporated (the Merger). Both Ameren and its
subsidiaries  are  subject  to  the  regulatory  provisions  of the  PUHCA.  The
operating  companies are engaged  principally in the  generation,  transmission,
distribution  and  sale  of  electric  energy  and the  purchase,  distribution,
transportation  and sale of natural gas in the states of Missouri and  Illinois.
Contracts among the companies--dealing with jointly-owned generating facilities,
interconnecting  transmission  lines,  and the  exchange of electric  power--are
regulated by the Federal Energy  Regulatory  Commission (FERC) or the Securities
and Exchange Commission (SEC).  Administrative  support services are provided to
the Registrant by a separate Ameren  subsidiary,  Ameren Services  Company.  The
Registrant  serves 1.1 million  electric  and 124,000 gas  customers in a 24,500
square-mile area of Missouri and Illinois, including Metropolitan St. Louis.

The Registrant also has a 40 percent  interest in Electric  Energy,  Inc. (EEI),
which is  accounted  for under the  equity  method of  accounting.  EEI owns and
operates an  electric  generating  and  transmission  facility in Illinois  that
supplies  electric  power  primarily to a uranium  enrichment  plant  located in
Paducah, Kentucky.

Note 2 - Financial  statement note  disclosures,  normally included in financial
statements prepared in conformity with generally accepted accounting principles,
have been omitted in this Form 10-Q pursuant to the Rules and Regulations of the
SEC.  However,  in the opinion of the Registrant,  the disclosures  contained in
this Form 10-Q are adequate to make the  information  presented not  misleading.
See Notes to Financial Statements included in the 1999 Form 10-K for information
relevant to the  financial  statements  contained  in this Form 10-Q,  including
information as to the significant accounting policies of the Registrant.

Note 3 - In the opinion of the Registrant the interim financial statements filed
as part of this Form 10-Q  reflect all  adjustments,  consisting  only of normal
recurring  adjustments,  necessary  for a fair  statement of the results for the
periods presented. The Registrant's financial statements were prepared to permit
the information required in the Financial Data Schedule (FDS), Exhibit 27, to be
directly  extracted from the filed statements.  The FDS amounts correspond to or
are calculable  from the amounts  reported in the financial  statements or notes
thereto.

Note 4 - Due to the  effect of  weather  on sales and  other  factors  which are
characteristic of public utility  operations,  financial results for the periods
ended September 30, 2000 and 1999, are not necessarily  indicative of trends for
any three-month, nine-month or 12-month period.

Note 5 - In July 1995, the Missouri Public Service  Commission  (MoPSC) approved
an agreement  establishing  contractual  obligations  involving the Registrant's
Missouri  retail  electric  rates.   Included  was  a  three-year   experimental
alternative  regulation  plan  (the  Original  Plan)  that ran from July 1, 1995
through June 30, 1998,  which provided that earnings in those years in excess of
a 12.61%  regulatory  return on equity (ROE) be shared equally between customers
and  stockholders,  and earnings  above a 14% ROE be credited to customers.  The
formula for  computing  the credit  used  twelve-month  results  ending June 30,
rather than calendar year earnings.

The MoPSC staff proposed  adjustments  to the  Registrant's  estimated  customer
credit for the final year of the Original  Plan ended June 30, 1998,  which were
the  subject of  regulatory  proceedings  before the MoPSC in 1999.  In December
1999,  the MoPSC issued a Report and Order  (Order)  concerning  these  proposed
adjustments.  Based on the provisions of that Order, the Registrant  revised its
estimated final year credit to $31 million.  Subsequently, in December 1999, the
Registrant  filed a request for  rehearing  of the Order with the MoPSC,  asking
that  it  reconsider  its  decision  to  adopt  certain  of  the  MoPSC  staff's
adjustments.  The  request  was denied by the MoPSC and in  February  2000,  the
Registrant  filed a Petition

                                      -11-

<PAGE>

for Writ of Review with the Circuit  Court of Cole
County,  Missouri,  requesting that the Order be reversed. The appeal is pending
and the ultimate  outcome can not be predicted;  however,  the final decision is
not expected to materially impact the financial condition, results of operations
or liquidity of the  Registrant.  A partial stay of the Order was granted by the
Court pending the appeal.

A new three-year  experimental  alternative  regulation plan (the New Plan) was
included in the joint  agreement  authorized  by the MoPSC in its February  1997
order  approving the Merger.  Like the Original Plan, the New Plan requires that
earnings  over a 12.61  percent  ROE up to a 14  percent  ROE be shared  equally
between  customers and  stockholders.  The New Plan also returns to customers 90
percent of all earnings above a 14 percent ROE up to a 16 percent ROE.  Earnings
above a 16 percent ROE are  credited  entirely to  customers.  The New Plan runs
from July 1, 1998 through June 30, 2001. At September 30, 2000,  the  Registrant
has recorded  estimated credits that the Registrant  expects to pay its Missouri
electric  customers  of $20  million,  $35  million and $25 million for the plan
years ended June 30,  2001,  June 30,  2000,  and June 30,  1999,  respectively.
During the three months ended  September 30, 2000,  the  Registrant  recorded an
estimated credit of $20 million (8 cents per share) for the plan year ended June
30, 2001.  No credits  under the New Plan were  recorded  during the same period
last year. For the nine months ended September 30, 2000, the Registrant recorded
estimated,  credits,  in total of $35 million (15 cents per share) for plan year
under the New Plan  compared  to $30  million  (12 cents per share) in the prior
period.  These credits were reflected as a reduction in electric  revenues.  The
final  amount of the  credits  will  depend on several  factors,  including  the
Registrant's earnings for the respective 12 months ended June 30.

In November 2000, the MoPSC approved a stipulation  and agreement of the parties
regarding  the  credit to be paid by the  Registrant  to its  Missouri  electric
customers for the plan year ended June 30, 1999.  Based on the provisions of the
stipulation and agreement,  the credit to be paid to electric  customers for the
plan year ended June 30, 1999 will approximate $22 million.

The joint  agreement  approved by the MoPSC in its February 1997 Order approving
the Merger also provided for a Missouri  electric rate decrease,  retroactive to
September  1, 1998,  based on the  weather-adjusted  average  annual  credits to
customers  under the Original  Plan. The rate decrease was impacted by the Order
issued by the MoPSC in December 1999  relating to the  estimated  credit for the
third year of the Original Plan and a settlement reached between the Registrant,
the  MoPSC  staff  and  other  parties   relating  to  the  calculation  of  the
weather-adjusted  credits. Based on those results, the Registrant estimates that
its Missouri  electric rate decrease will be $17 million on an annualized basis.
This  estimate  is subject to the final  outcome of the  above-referenced  court
appeal of the Order.

Note 6 - The Registrant has  transactions  in the normal course of business with
other Ameren  subsidiaries.  These transactions are primarily comprised of power
purchases and sales and services received or rendered.  Intercompany receivables
included in other accounts and notes receivable were  approximately  $33 million
and $15 million,  respectively,  as of September 30, 2000 and December 31, 1999.
Intercompany   payables   included  in  accounts  and  wages   payable   totaled
approximately  $102 million and $25 million,  respectively,  as of September 30,
2000 and December 31, 1999.

Also, the Registrant has the ability to borrow up to approximately  $525 million
from  Ameren or  AmerenCIPS  through  a  regulated  money  pool  agreement.  The
regulated  money pool was  established  to  coordinate  and  provide for certain
short-term cash and working capital  requirements  and is administered by Ameren
Services Company.  Interest is calculated at varying rates of interest depending
on the  composition of internal and external funds in the regulated  money pool.
At September 30, 2000, the Registrant had outstanding  intercompany  receivables
of $158 million and $196 million available through the regulated money pool.

Note 7- The  Registrant's  union employees are represented by the  International
Brotherhood  of  Electrical  Workers and the  International  Union of  Operating
Engineers.   These  employees  comprise   approximately  65%  of  the  Company's
workforce.   New  contracts  with  collective   bargaining  units   representing
approximately  46% of these  employees were ratified in 1999 with terms expiring
in  2002.  New  contracts  with   collective   bargaining   units   representing
approximately  28% of these  employees were ratified in 2000 with terms expiring
in 2003. In August 2000, the remaining collective  bargaining units representin

                                      -12-

<PAGE>

approximately 26% of the Registrant's union employees, ratified the Registrant's
last, best and final offer for a new contract with a term expiring in 2003.

Note 8- On November 9, 2000, the Registrant  announced its intention to withdraw
from the  Midwest  Independent  System  Operator  and to  become a member of the
Alliance  Regional  Transmission   Organization   (Alliance  RTO),  pending  the
necessary regulatory approvals.  The Alliance RTO, including its rate structure,
is still  subject  to  approval  by the FERC.  Accordingly,  the  Registrant  is
currently  unable to determine the impact that operation of the Alliance RTO, or
the  withdrawal  from the Midwest  ISO,  will have on its  financial  condition,
results of operations or liquidity.

Note 9- In  September  2000,  the  Registrant  filed a request with the Illinois
Commerce  Commission (ICC) seeking  authorization to transfer its Illinois-based
electric  and natural  gas  business  and its  Illinois-based  distribution  and
transmission   assets  and  personnel  to  AmerenCIPS.   The   distribution  and
transmission assets and related liabilities will be transferred from AmerenUE to
AmerenCIPS  at  historical  net book value of  approximately  $101  million.  In
connection with this transaction, the Registrant will receive from AmerenCIPS an
intercompany  note receivable of approximately  $50 million.  The balance of the
assets will be transferred to AmerenCIPS in the form of a capital  contribution.
In October 2000, the  Registrant  filed a request with the MoPSC for approval of
this transfer.  The transfer is also subject to regulatory filings and approvals
of the Federal Energy Regulatory  Commission (FERC) and the Securities  Exchange
Commission.

                                      -13-

<PAGE>

                           PART II. OTHER INFORMATION

ITEM 1. LEGAL PROCEEDINGS
        -----------------

On June 23,  2000,  the United  States  Environmental  Protection  Agency  (EPA)
notified the Registrant and numerous other companies that certain  properties in
Sauget,  Illinois,  may  contain  soil  and  groundwater   contamination.   From
approximately  1926 until  1976,  the  Registrant  operated  a power  generating
facility and currently owns and operates electric transmission facilities in the
area.  The  Registrant  has  joined  with nine  other  companies  to  perform an
investigation  of soil and  groundwater  conditions in the area and is currently
negotiating  with the EPA the terms of an  Administrative  Order on Consent that
provides for the performance of such work. The investigation process should take
approximately  two years.  At this time, the Registrant is unable to predict the
ultimate impact of the Sauget site on its future financial condition, results of
operations or liquidity.

On September 25, 2000, the United States Department of
Justice  was  granted  leave by the  United  States  District  Court -  Southern
District  of  Illinois  to  add  numerous  additional  parties,   including  the
Registrant,  to a  pre-existing  lawsuit  between the  government  and  Monsanto
Chemical  Company and others.  The  government  seeks recovery of response costs
under the Comprehensive  Environmental  Response  Compensation  Liability Act of
1980  (commonly  known as CERCLA or Superfund),  incurred in connection  with an
Illinois  Superfund  site  referred  to as Dead  Creek.  The  Registrant  owns a
transmission  line which traverses the creek.  The Registrant  believes that the
final  resolution of this lawsuit will not have a material adverse effect on its
financial position, results of operations or liquidity.

     ITEM 6. EXHIBITS AND REPORTS ON FORM 8-K
             --------------------------------

          (a)  Exhibits.

               Exhibit 12 -  Computation  of Ratio of Earnings to Fixed  Charges
               and  Preferred  Stock  Dividend  Requirements,  12  Months  Ended
               September 30, 2000.

               Exhibit 27 - Financial Data Schedule.

          (b)  Reports on Form 8-K. None.


                                   SIGNATURES

Pursuant to the  requirements  of the Securities  Exchange Act of 1934, the
Registrant  has duly  caused  this  report  to be  signed  on its  behalf by the
undersigned thereunto duly authorized.

                             UNION ELECTRIC COMPANY
                                  (Registrant)


                                       By  /S/ Donald E. Brandt
                                           ----------------------
                                             Senior Vice President
                                        Finance and Corporate Services
                                         (Principal Financial Officer)


Date:  November 14, 2000

                                      -14-