<PAGE>   1

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

                             ---------------------

                                   FORM 10-Q

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

                  FOR THE QUARTERLY PERIOD ENDED JUNE 30, 2000

                                       OR

[ ]             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 1-4101

                             ---------------------

                         TENNESSEE GAS PIPELINE COMPANY
             (Exact Name of Registrant as Specified in its Charter)

<TABLE>
<S>                                            <C>
                   DELAWARE                                      74-1056569
         (State or Other Jurisdiction                         (I.R.S. Employer
      of Incorporation or Organization)                     Identification No.)

           EL PASO ENERGY BUILDING
            1001 LOUISIANA STREET
                HOUSTON, TEXAS                                     77002
   (Address of Principal Executive Offices)                      (Zip Code)
</TABLE>

       Registrant's Telephone Number, Including Area Code: (713) 420-2131

     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 [ ]

     Indicate the number of shares outstanding of each of the issuer's classes
of common stock, as of the latest practicable date.

     Common Stock, par value $5 per share. Shares outstanding on August 7, 2000:
208

     TENNESSEE GAS PIPELINE COMPANY MEETS THE CONDITIONS OF GENERAL INSTRUCTION
H(1)(a) AND (b) OF FORM 10-Q AND IS THEREFORE FILING THIS REPORT WITH A REDUCED
DISCLOSURE FORMAT AS PERMITTED BY SUCH INSTRUCTION.

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<PAGE>   2

                        PART I -- FINANCIAL INFORMATION

ITEM 1. FINANCIAL STATEMENTS

                         TENNESSEE GAS PIPELINE COMPANY

                  CONDENSED CONSOLIDATED STATEMENTS OF INCOME
                                 (IN MILLIONS)
                                  (UNAUDITED)

<TABLE>
<CAPTION>
                                                             QUARTER            SIX MONTHS
                                                          ENDED JUNE 30,      ENDED JUNE 30,
                                                          --------------      --------------
                                                          2000      1999      2000      1999
                                                          ----      ----      ----      ----
<S>                                                       <C>       <C>       <C>       <C>
Operating revenues......................................  $174      $175      $360      $362
                                                          ----      ----      ----      ----
Operating expenses
  Operation and maintenance.............................    50        25       103        74
  Depreciation, depletion, and amortization.............    34        34        69        68
  Taxes, other than income taxes........................    11        12        23        24
                                                          ----      ----      ----      ----
                                                            95        71       195       166
                                                          ----      ----      ----      ----
Operating income........................................    79       104       165       196
Other income
  Equity investment earnings............................     2         2         6         5
  Other, net............................................     3         1         5         7
                                                          ----      ----      ----      ----
                                                             5         3        11        12
                                                          ----      ----      ----      ----
Income before interest and income taxes.................    84       107       176       208
                                                          ----      ----      ----      ----
Non-affiliated interest and debt expense................    27        31        61        64
Affiliated interest income, net.........................    (3)       (8)      (14)      (16)
Income tax expense......................................    20        26        43        52
                                                          ----      ----      ----      ----
                                                            44        49        90       100
                                                          ----      ----      ----      ----
Net income..............................................  $ 40      $ 58      $ 86      $108
                                                          ====      ====      ====      ====
</TABLE>

                            See accompanying notes.

                                        1
<PAGE>   3

                         TENNESSEE GAS PIPELINE COMPANY

                     CONDENSED CONSOLIDATED BALANCE SHEETS
                      (IN MILLIONS, EXCEPT SHARE AMOUNTS)
                                  (UNAUDITED)

<TABLE>
<CAPTION>
                                                              JUNE 30,   DECEMBER 31,
                                                                2000         1999
                                                              --------   ------------
<S>                                                           <C>        <C>
                                       ASSETS
Current assets
  Cash and cash equivalents.................................   $    4       $    4
  Accounts and notes receivable, net........................      253          624
  Materials and supplies....................................       18           17
  Deferred income tax benefit...............................       49           44
  Other.....................................................       11           18
                                                               ------       ------
          Total current assets..............................      335          707
Property, plant, and equipment, net.........................    4,502        4,488
Other.......................................................      224          226
                                                               ------       ------
          Total assets......................................   $5,061       $5,421
                                                               ======       ======

LIABILITIES AND STOCKHOLDER'S EQUITY

Current liabilities
  Accounts payable..........................................   $  201       $  216
  Short-term borrowings (including current maturities of
     long-term debt)........................................      135          650
  Taxes payable.............................................      119          105
  Other.....................................................       93           85
                                                               ------       ------
          Total current liabilities.........................      548        1,056
Long-term debt, less current maturities.....................    1,354        1,353
Deferred income taxes.......................................    1,217        1,175
Other.......................................................      294          275

Commitments and contingencies

Stockholder's equity
  Common stock, par value $5 per share; authorized 300
     shares; issued 208 shares..............................       --           --
  Additional paid-in capital................................    1,388        1,388
  Retained earnings.........................................      260          174
                                                               ------       ------
          Total stockholder's equity........................    1,648        1,562
                                                               ------       ------
          Total liabilities and stockholder's equity........   $5,061       $5,421
                                                               ======       ======
</TABLE>

                            See accompanying notes.

                                        2
<PAGE>   4

                         TENNESSEE GAS PIPELINE COMPANY

                CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS
                                 (IN MILLIONS)
                                  (UNAUDITED)

<TABLE>
<CAPTION>
                                                                SIX MONTHS
                                                                   ENDED
                                                                 JUNE 30,
                                                              ---------------
                                                              2000       1999
                                                              -----      ----
<S>                                                           <C>        <C>
Cash flows from operating activities
  Net income................................................  $  86      $108
  Adjustments to reconcile net income to net cash from
     operating activities
     Depreciation, depletion, and amortization..............     69        68
     Deferred income tax expense............................     36        16
     Other..................................................     (6)        1
  Working capital changes, net of non-cash transactions.....    (45)      (65)
  Other.....................................................     26         3
                                                              -----      ----
          Net cash provided by operating activities.........    166       131
                                                              -----      ----
Cash flows from investing activities
  Purchases of property, plant, and equipment...............    (56)      (49)
  Additions to investments..................................     --        (7)
  Net change in other affiliated advances receivable........    442        --
  Other.....................................................     (3)       (3)
                                                              -----      ----
          Net cash provided by (used in) investing
           activities.......................................    383       (59)
                                                              -----      ----
Cash flows from financing activities
  Net repayments of commercial paper........................   (514)      (79)
  Net change in other affiliated advances payable...........    (35)        5
                                                              -----      ----
          Net cash used in financing activities.............   (549)      (74)
                                                              -----      ----
Decrease in cash and cash equivalents.......................     --        (2)
Cash and cash equivalents
          Beginning of period...............................      4         5
                                                              -----      ----
          End of period.....................................  $   4      $  3
                                                              =====      ====
</TABLE>

                            See accompanying notes.

                                        3
<PAGE>   5

                         TENNESSEE GAS PIPELINE COMPANY

              NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS
                                  (UNAUDITED)

1. BASIS OF PRESENTATION

     Our 1999 Annual Report on Form 10-K includes a summary of our significant
accounting policies and other disclosures. You should read it in conjunction
with this Quarterly Report on Form 10-Q. The condensed consolidated financial
statements at June 30, 2000, and for the quarters and six months ended June 30,
2000 and 1999, are unaudited. The condensed consolidated balance sheet at
December 31, 1999, is derived from the audited financial statements. These
financial statements do not include all disclosures required by accounting
principles generally accepted in the United States, but have been prepared
pursuant to the rules and regulations of the U.S. Securities and Exchange
Commission. In our opinion, all material adjustments, all of which are of a
normal, recurring nature, have been made to fairly present our results of
operations. Information for any interim period may not necessarily indicate the
results of operations for the entire year due to the seasonal nature of our
businesses. The prior period information includes reclassifications which were
made to conform to the current presentation. These reclassifications have no
effect on our reported net income or stockholder's equity.

2. PROPERTY, PLANT, AND EQUIPMENT

     Our property, plant, and equipment consisted of the following at June 30,
2000 and December 31, 1999:

<TABLE>
<CAPTION>
                                                               2000     1999
                                                              ------   ------
                                                               (IN MILLIONS)
<S>                                                           <C>      <C>
Property, plant, and equipment, at cost.....................  $2,531   $2,479
Less accumulated depreciation and depletion.................     331      304
                                                              ------   ------
                                                               2,200    2,175
Additional acquisition cost assigned to utility plant, net
  of accumulated amortization...............................   2,302    2,313
                                                              ------   ------
Total property, plant, and equipment, net...................  $4,502   $4,488
                                                              ======   ======
</TABLE>

3. DEBT AND OTHER CREDIT FACILITIES

     In August 2000, El Paso Energy replaced its $1,250 million and $750 million
revolving credit facilities with a $2 billion 364-day renewable revolving credit
and competitive advance facility and a $1 billion 3-year revolving credit and
competitive advance facility. We are a designated borrower under these new
facilities. Our interest rate for these facilities varies and would have been
LIBOR plus 41 basis points as of June 30, 2000. The available credit under these
facilities is expected to be used for El Paso Energy's general corporate
purposes including, but not limited to, supporting our commercial paper
programs.

     At June 30, 2000, our weighted average interest rate on short-term
borrowings was 7.2%, and at December 31, 1999, it was 6.6%. We had the following
short-term borrowings, including current maturities of long-term debt, at June
30, 2000 and December 31, 1999:

<TABLE>
<CAPTION>
                                                              2000    1999
                                                              -----   -----
                                                              (IN MILLIONS)
<S>                                                           <C>     <C>
Commercial paper............................................  $135    $649
Current maturities of long-term debt........................    --       1
                                                              ----    ----
                                                              $135    $650
                                                              ====    ====
</TABLE>

                                        4
<PAGE>   6

4. COMMITMENTS AND CONTINGENCIES

  Rates and Regulatory Matters

     In April 1997, the Federal Energy Regulatory Commission (FERC) approved the
settlement of all issues related to the recovery of our Gas Supply Realignment
(GSR) and other transition costs and related proceedings. Under the terms of
this agreement, we are entitled to collect up to $770 million from our
customers, $693 million through a demand surcharge and $77 million through an
interruptible transportation surcharge. The demand portion has been fully
collected. As of June 30, 2000, $50 million of the interruptible transportation
surcharge had been collected. There is no time limit for collection of the
interruptible transportation surcharge. The terms of this agreement also provide
for a rate case moratorium through November 2000 (subject to certain limited
exceptions) and an escalating rate cap, indexed to inflation, through October
2005, for some of our customers. In March 2000, we provided a report to our firm
and interruptible customers detailing our GSR costs and collections through
December 31, 1999. At December 31, 1999, we were over-collected from our firm
customers by approximately $30 million. We will be required to refund amounts
collected in excess of each firm customer's share of the final transition costs
based on the final GSR reconciliation report, which will be filed in March 2001.
We do not expect future refunds to have a material adverse effect on our
financial position, results of operations, or cash flows.

     In December 1996, we filed for a general rate increase with FERC. In
October 1998, FERC approved our settlement resolving that proceeding. The
settlement included a structural rate design change that resulted in a larger
portion of our transportation revenues being dependent upon throughput. One of
our competitors filed a petition for review of the settlement with the Court of
Appeals, which remanded the case to FERC to respond to the competitor's argument
that our cost allocation methodology deterred the development of market centers.
Comments were filed with FERC in January 1999. In June 2000, the FERC issued an
order setting the competitor's issues for hearing before an Administrative Law
Judge (ALJ). The FERC directed the ALJ to develop a record on:

     - existing and potential market centers and whether our existing rate
       structure affected their development;

     - whether the location of our existing rate zone boundaries affected the
       development of market centers;

     - whether our systemwide allocation of cost of service inhibited market
       centers; and

     - if our rate design is changed, the opportunity to recover stranded costs.

     The FERC directed the ALJ to set a pre-hearing conference within twenty
days of the order. In July 2000, we filed a joint motion with the FERC to
postpone the pre-hearing conference to permit settlement discussions. The ALJ
granted this postponement until no later than August 30, 2000.

     We have contracts covering a portion of our firm transportation capacity
which have various terms of maturity. As of June 30, 2000, 20 percent of our
firm transportation capacity contracts will expire by November 2000. We are
aggressively pursuing the renegotiation and renewal of expiring contracts and
the sale of excess capacity under firm transportation arrangements. However, it
is uncertain if future contracts will be on terms as favorable to us as those
that exist currently. Also, new and renewed contracts can be disputed by
customers and other groups, and there is no certainty that regulators or other
jurisdictional bodies will not intercede in the re-contracting process and alter
the ultimate outcome of our efforts.

     As an interstate pipeline, we are subject to FERC audits of our books and
records. Also, from time to time, the FERC audit staff requests supporting
documentation from us as evidence of our compliance.

     As our rate and regulatory matters are fully and unconditionally resolved,
we may either recognize additional refund obligations, non-cash write-downs of
previously established assets, or non-cash benefits to finalize previously
estimated liabilities. While we cannot predict with certainty the final outcome
or timing of the final resolution of our rates and regulatory matters, the
outcome of our current re-contracting efforts, or the outcome of ongoing
industry trends and initiatives, we believe that the ultimate resolution of
these pending

                                        5
<PAGE>   7

rate and regulatory matters will not have a material adverse effect on our
financial position, results of operations, or cash flows.

  Legal Proceedings

     In February 1998, the United States and the State of Texas filed in a U.S.
District Court a Comprehensive Environmental Response, Compensation and
Liability Act (CERCLA) cost recovery action against fourteen companies,
including certain of our current and former affiliated companies and us,
relating to the Sikes Disposal Pits Superfund Site located in Harris County,
Texas. The suit claims that the United States and the State of Texas have spent
over $125 million in remediating Sikes, and seeks to recover that amount plus
interest from the defendants to the suit. Although an investigation relating to
Sikes is in the preliminary stages, we believe that the amount of material, if
any, disposed at Sikes by our former affiliates was small, possibly de minimis.
However, the plaintiffs have alleged that the defendants are each jointly and
severally liable for the entire remediation costs and have also sought a
declaration of liability for future response costs such as groundwater
monitoring.

     We are a party in proceedings involving federal and state authorities
regarding the past use of a lubricant containing polychlorinated biphenyls
(PCBs) in our starting air systems. We have executed a consent order with the
EPA governing the remediation of some compressor stations and are working with
the EPA and the relevant states regarding those remediation activities. Also, we
are working with the Pennsylvania and New York environmental agencies regarding
remediation and post-remediation activities at the Pennsylvania and New York
stations.

     In November 1988, the Kentucky environmental agency filed a complaint in a
Kentucky state court alleging that we discharged pollutants into the waters of
the state and disposed of PCBs without a permit. The agency sought an injunction
against future discharges, an order to remediate or remove PCBs, and a civil
penalty. We entered into agreed orders with the agency to resolve many of the
issues raised in the original allegations, have received water discharge permits
from the agency for its Kentucky compressor stations, and continue to work to
resolve the remaining issues. The relevant Kentucky compressor stations are
scheduled to be characterized and remediated under the consent order with the
EPA.

     We are a named defendant in actions brought by Jack Grynberg on behalf of
the U.S. Government under the False Claims Act. Generally, these complaints
allege an industry-wide conspiracy to under report the heating value as well as
the volumes of the natural gas produced from federal and Native American lands,
which deprived the U.S. Government of royalties. We have also been named as a
defendant in a similar class action suit, Quinque Operating Company v. Gas
Pipelines. This complaint alleges that the defendants mismeasured natural gas
volumes and heating content of natural gas on non-federal and non-Native
American lands. The Quinque complaint was transferred to the same court handling
the Grynberg complaint. We believe both complaints are without merit.

     We are also a named defendant in numerous lawsuits and a named party in
numerous governmental proceedings arising in the ordinary course of our
business.

     While the outcome of the matters discussed above cannot be predicted with
certainty, we do not expect the ultimate resolution of these matters to have a
material adverse effect on our financial position, results of operations, or
cash flows.

  Environmental

     We are subject to extensive federal, state, and local laws and regulations
governing environmental quality and pollution control. These laws and
regulations require us to remove or remedy the effect on the environment of the
disposal or release of specified substances at current and former operating
sites. As of June 30, 2000, we had reserved $102 million for expected
environmental costs.

     In addition, we expect to make capital expenditures of approximately $3
million in 2000 and a total of $80 million for the years 2001 through 2007 for
environmental matters primarily relating to compliance with air regulations and
control of water discharges. Some of our subsidiaries have been designated, have
received
                                        6
<PAGE>   8

notice that they could be designated, or have been asked for information to
determine whether they could be designated as a potentially responsible party
with respect to 4 active sites under CERCLA.

     It is possible that new information or future developments could require us
to reassess our potential exposure related to environmental matters. We may
incur significant costs and liabilities in order to comply with existing
environmental laws and regulations. It is also possible that other developments,
such as increasingly strict environmental laws and regulations, and claims for
damages to property, employees, other persons and the environment resulting from
our current or past operations, could result in substantial costs and
liabilities in the future. As this information becomes available, or other
relevant developments occur, we will adjust our accrual amounts accordingly.
While there are still uncertainties relating to the ultimate costs we may incur,
based upon our evaluation and experience to date, we believe the recorded
reserves are adequate.

5. NEW ACCOUNTING PRONOUNCEMENTS NOT YET ADOPTED

  Accounting for Derivative Instruments and Hedging Activities

     In June 1998, the Financial Accounting Standards Board issued Statement of
Financial Accounting Standards (SFAS) No. 133, Accounting for Derivative
Instruments and Hedging Activities, to establish accounting and reporting
standards for derivative instruments, including derivative instruments embedded
in other contracts, and for hedging activities. This pronouncement requires us
to classify derivatives as either assets or liabilities on the balance sheet,
with a corresponding offset to income or other comprehensive income, and measure
those instruments at fair value. If certain conditions are met, we may
specifically designate a derivative as a hedge of:

     - the exposure to changes in the fair value of a recognized asset or
       liability or an unrecognized firm commitment;

     - the exposure to variable cash flows of a forecasted transaction; or

     - the foreign currency exposure of a net investment in a foreign operation,
       an unrecognized firm commitment, an available-for-sale security, or a
       foreign-currency-denominated forecasted transaction.

     The accounting for the changes in the fair value of a derivative depends on
the intended use of the derivative and the resulting designation.

     SFAS No. 137, Deferral of the Effective Date of SFAS 133, amended the
standard in June 1999 to defer the effective date. Consequently, SFAS No. 133
will be effective for us January 1, 2001.

     In June 2000, the Financial Accounting Standards Board issued SFAS No. 138,
Accounting for Certain Derivative Instruments and Certain Hedging Activities,
which also amended SFAS No. 133. The amendment:

     - expands the normal purchases and sales exception;

     - redefines specific risks that can be designated as hedges;

     - allows recognition of foreign-currency-denominated assets and liabilities
       as hedged items; and

     - permits intercompany derivatives to be designated as hedging instruments
       for foreign currency risk if the hedge is offset by an unrelated third
       party on a net basis (netting risks is permitted only for foreign
       currency transactions).

We are currently evaluating the effects these pronouncements will have on our
financial position, results of operations, or cash flows.

  Staff Accounting Bulletin No. 101

     In December 1999, the Securities and Exchange Commission issued Staff
Accounting Bulletin (SAB) No. 101, Revenue Recognition in Financial Statements,
to provide guidance for revenue recognition issues and disclosure requirements.
SAB No. 101 offers guidelines, examples, and explanations for uncertain matters
relating to the recognition of revenue and will be effective for us in the
fourth quarter of 2000. We do not believe the adoption of SAB No. 101 will have
a material impact on our financial position, results of operations, or cash
flows.

                                        7
<PAGE>   9

ITEM 2. MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS
        OF OPERATIONS

     The information contained in Item 2 updates, and you should read it in
conjunction with, information disclosed in Part II, Items 7, 7A, and 8, in our
Annual Report on Form 10-K for the year ended December 31, 1999, in addition to
the financial statements and notes presented in Item 1 of this Quarterly Report
on Form 10-Q.

                             RESULTS OF OPERATIONS

<TABLE>
<CAPTION>
                                                                         SIX MONTHS
                                                      QUARTER ENDED         ENDED
                                                        JUNE 30,          JUNE 30,
                                                     ---------------   ---------------
                                                      2000     1999     2000     1999
                                                     ------   ------   ------   ------
                                                        (IN MILLIONS, EXCEPT VOLUME
                                                                 AMOUNTS)
<S>                                                  <C>      <C>      <C>      <C>
Operating revenues.................................  $  174   $  175   $  360   $  362
Operating expenses.................................     (95)     (71)    (195)    (166)
Other income.......................................       5        3       11       12
                                                     ------   ------   ------   ------
  EBIT.............................................  $   84   $  107   $  176   $  208
                                                     ======   ======   ======   ======
Throughput volumes (BBtu/d)(1).....................   4,027    4,335    4,453    4,585
                                                     ======   ======   ======   ======
</TABLE>

---------------

(1) BBtu/d means billion British thermal units per day.

SECOND QUARTER 2000 COMPARED TO SECOND QUARTER 1999

     Operating revenues for the quarter ended June 30, 2000, were $1 million
lower than 1999. Lower revenues from the favorable resolution of a regulatory
issue during the second quarter of 1999 were offset by higher revenues from
contract settlements associated with El Paso Energy's sale of the East Tennessee
Pipeline system, as well as an increase in revenues from transportation and
other services.

     Operating expenses for the quarter ended June 30, 2000, were $24 million
higher than 1999. The increase was due to the favorable resolution of our
customer imbalance mechanism in 1999 partially offset by lower shared services
allocations following El Paso Energy's merger with Sonat Inc.

SIX MONTHS ENDED 2000 COMPARED TO SIX MONTHS ENDED 1999

     Operating revenues for the six months ended June 30, 2000, were $2 million
lower than 1999. The decrease was due to the favorable resolution of regulatory
issues in 1999 and was partially offset by higher revenues from contract
settlements associated with El Paso Energy's sale of the East Tennessee Pipeline
system as well as increases in revenues from transportation and other services
in 2000.

     Operating expenses for the six months ended June 30, 2000, were $29 million
higher than 1999. The increase was due to the favorable resolution of our
customer imbalance mechanism in 1999 partially offset by lower shared services
allocations following El Paso Energy's merger with Sonat.

NON-AFFILIATED INTEREST AND DEBT EXPENSE

     Non-affiliated interest and debt expense for the quarter and six months
ended June 30, 2000, was $4 million and $3 million lower than the same periods
of 1999 due to a decrease in average commercial paper borrowings and higher
capitalized interest.

AFFILIATED INTEREST INCOME, NET

     Affiliated interest income, net for the quarter and six months ended June
30, 2000, was $5 million and $2 million lower than for the same periods of 1999
due to decreased average advances to El Paso Energy in 2000.

                                        8
<PAGE>   10

INCOME TAX EXPENSE

     Income tax expense for the quarters ended June 30, 2000 and 1999, was $20
million and $26 million, resulting in an effective tax rate of 33% and 31%.
Income tax expense for the six months ended June 30, 2000 and 1999, was $43
million and $52 million, resulting in an effective tax rate of 33% for each
period. The effective tax rates were lower than the statutory rate of 35% due to
state income tax benefits.

OTHER

     In May 2000, El Paso Energy formed Clydesdale Associates, L.P., a limited
partnership, and several other separate legal entities, for the purpose of
generating funds for El Paso Energy to invest in capital projects and other
assets. Certain assets of El Paso Energy, including proceeds we receive from
renting our office building in Houston, Texas, collateralize the funds generated
by the structure.

                                        9
<PAGE>   11

           CAUTIONARY STATEMENT REGARDING FORWARD-LOOKING STATEMENTS

     We have made statements in this document that constitute forward-looking
statements, as that term is defined in the Private Securities Litigation Reform
Act of 1995. These statements are subject to risks and uncertainties.
Forward-looking statements include information concerning possible or assumed
future results of operations. These statements may relate to information or
assumptions about:

     - capital and other expenditures;

     - dividends;

     - financing plans;

     - capital structure;

     - cash flow;

     - pending legal proceedings and claims, including environmental matters;

     - future economic performance;

     - operating income;

     - cost savings;

     - management's plans; and

     - goals and objectives for future operations.

     Important factors that could cause actual results to differ materially from
estimates or projections contained in forward-looking statements include, among
others, the following:

     - the increasing competition within our industry;

     - the timing and extent of changes in commodity prices for natural gas and
       power;

     - the uncertainties associated with customer contract expirations on our
       pipeline systems;

     - the potential contingent liabilities and tax liabilities related to our
       acquisitions; and

     - the conditions of equity and other capital markets.

     These risk factors are more fully described in our other filings with the
Securities and Exchange Commission, including our Annual Report on Form 10-K for
the year ended December 31, 1999.

ITEM 3. QUANTITATIVE AND QUALITATIVE DISCLOSURES ABOUT MARKET RISK

     This information updates, and you should read it in conjunction with,
information disclosed in Part II, Item 7A in our Annual Report on Form 10-K for
the year ended December 31, 1999, in addition to the information presented in
Items 1 and 2 of this Quarterly Report on Form 10-Q.

     There are no material changes in market risk from those reported in our
Annual Report on Form 10-K for the year ended December 31, 1999.

                                       10
<PAGE>   12

                          PART II -- OTHER INFORMATION

ITEM 1. LEGAL PROCEEDINGS

     See Part I, Financial Information, Note 4, which is incorporated herein by
reference.

ITEM 2. CHANGES IN SECURITIES AND USE OF PROCEEDS

     None.

ITEM 3. DEFAULTS UPON SENIOR SECURITIES

     None.

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

     None.

ITEM 5. OTHER INFORMATION

     None.

ITEM 6. EXHIBITS AND REPORTS ON FORM 8-K

a. Exhibits

     Each exhibit identified below is filed as a part of this report.

<TABLE>
<CAPTION>
        EXHIBIT
         NUMBER
        -------                                  DESCRIPTION
<C>                      <S>
          27             -- Financial Data Schedule
</TABLE>

     Undertaking

          The undersigned hereby undertakes, pursuant to Regulation S-K, Item
     601(b), paragraph (4)(iii), to furnish to the U.S. Securities and Exchange
     Commission, upon request, all constituent instruments defining the rights
     of holders of long-term debt of Tennessee Gas Pipeline Company and its
     consolidated subsidiaries not filed herewith for the reason that the total
     amount of securities authorized under any of such instruments does not
     exceed 10 percent of the total consolidated assets of Tennessee Gas
     Pipeline Company and its consolidated subsidiaries.

b. Reports on Form 8-K

     None.

                                       11
<PAGE>   13

                                   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.

                                            TENNESSEE GAS PIPELINE COMPANY

Date: August 9, 2000                               /s/ H. BRENT AUSTIN
                                            ------------------------------------
                                                      H. Brent Austin
                                                Executive Vice President and
                                                  Chief Financial Officer

Date: August 9, 2000                              /s/ JEFFREY I. BEASON
                                            ------------------------------------
                                                     Jeffrey I. Beason
                                            Senior Vice President and Controller
                                                 (Chief Accounting Officer)

                                       12
<PAGE>   14

                               INDEX TO EXHIBITS

<TABLE>
<CAPTION>
        EXHIBIT
         NUMBER
        -------                                  DESCRIPTION
<C>                      <S>
          27             -- Financial Data Schedule
</TABLE>