<PAGE>   1
 
================================================================================
 
                                 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, 1997
 
                                       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, HOUSTON, TEXAS                             77002
   (Address of Principal Executive Offices)                      (Zip Code)
</TABLE>
 
       Registrant's Telephone Number, Including Area Code: (713) 757-2131
 
     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.
 
<TABLE>
<CAPTION>
                    CLASS                                       OUTSTANDING
                    -----                                       -----------
<C>                                            <C>
   Common Stock, par value $5.00 per share,
            as of August 12, 1997                                208 shares
</TABLE>
 
     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
 
                                    GLOSSARY
 
     The following abbreviations, acronyms, or defined terms used in this Form
10-Q are defined below:
 
<TABLE>
<CAPTION>
                                                      DEFINITIONS
                                                      -----------
<S>                           <C>
Company.....................  Tennessee Gas Pipeline Company and its subsidiaries
Court of Appeals............  United States Court of Appeals for the District of Columbia
                              Circuit
Distributions...............  Various intercompany transfers and distributions which
                              restructured, divided and separated the businesses, assets
                              and liabilities of Old Tenneco and its subsidiaries so that
                              all the assets, liabilities and operations related to the
                              automotive parts, packaging and administrative services
                              businesses and the shipbuilding business were spun-off to
                              Old Tenneco's then existing common stockholders
EPG.........................  El Paso Natural Gas Company, unless the context otherwise
                              requires
EPTPC.......................  El Paso Tennessee Pipeline Co. (formerly Tenneco Inc.), an
                              indirect subsidiary of El Paso Natural Gas Company
FERC........................  The Federal Energy Regulatory Commission
GSR.........................  Gas supply realignment
Merger......................  The acquisition of El Paso Tennessee Pipeline Co. by El Paso
                              Natural Gas Company in December 1996
MW(s).......................  Megawatt(s)
New Tenneco.................  Tenneco Inc., subsequent to the Merger and Distributions,
                              consisting of the automotive parts, packaging and
                              administrative services businesses
Old Tenneco.................  Tenneco Inc. (renamed El Paso Tennessee Pipeline Co.), prior
                              to its acquisition by El Paso Natural Gas Company
PCB(s)......................  Polychlorinated biphenyl(s)
PRP(s)......................  Potentially responsible party(ies)
SFAS........................  Statement of Financial Accounting Standards
TGP.........................  Tennessee Gas Pipeline Company, a wholly owned subsidiary of
                              El Paso Tennessee Pipeline Co.
</TABLE>
 
                                        i
<PAGE>   3
 
                        PART I -- FINANCIAL INFORMATION
 
ITEM 1. FINANCIAL STATEMENTS
 
                         TENNESSEE GAS PIPELINE COMPANY
 
                 CONSOLIDATED AND COMBINED STATEMENTS OF INCOME
                                 (IN MILLIONS)
                                  (UNAUDITED)
 
<TABLE>
<CAPTION>
                                             SECOND QUARTER                           SIX MONTHS
                                             ENDED JUNE 30,                         ENDED JUNE 30,
                                   -----------------------------------    -----------------------------------
                                         1997               1996                1997               1996
                                   ----------------    ---------------    ----------------    ---------------
                                   POST-ACQUISITION    PRE-ACQUISITION    POST-ACQUISITION    PRE-ACQUISITION
                                     CONSOLIDATED         COMBINED          CONSOLIDATED         COMBINED
<S>                                <C>                 <C>                <C>                 <C>
Operating revenues...............        $785               $626               $1,474             $1,380
                                       ------               ----              -------             ------
Operating expenses
  Cost of gas and other
     products....................         590                400                1,053                886
  Operation and maintenance......          95                122                  187                252
  Finance charges................          --                 16                   --                 33
  Depreciation, depletion, and
     amortization................          34                 38                   77                 79
  Taxes, other than income
     taxes.......................          14                 14                   29                 31
                                       ------               ----              -------             ------
                                          733                590                1,346              1,281
                                       ------               ----              -------             ------
Operating income.................          52                 36                  128                 99
                                       ------               ----              -------             ------
Other (income) and expense
  Interest and debt expense......          26                  8                   39                 22
  Gain on sale of asset, net.....          --                  0                   --                (10)
  Other -- net...................         (21)               (32)                 (37)               (43)
                                       ------               ----              -------             ------
                                            5                (24)                   2                (31)
                                       ------               ----              -------             ------
Income before income taxes.......          47                 60                  126                130
Income taxes.....................          18                 24                   49                 51
                                       ------               ----              -------             ------
Net income.......................        $ 29               $ 36               $   77             $   79
                                       ======               ====              =======             ======
</TABLE>
 
 The accompanying Notes are an integral part of these Consolidated and Combined
                             Financial Statements.
 
                                        1
<PAGE>   4
 
                         TENNESSEE GAS PIPELINE COMPANY
 
                          CONSOLIDATED BALANCE SHEETS
                      (IN MILLIONS, EXCEPT SHARE AMOUNTS)
 
                                     ASSETS
 
<TABLE>
<CAPTION>
                                                               JUNE 30,
                                                                 1997        DECEMBER 31,
                                                              (UNAUDITED)        1996
                                                              -----------    ------------
<S>                                                           <C>            <C>
Current assets
  Cash and temporary investments............................    $   14          $   14
  Accounts and notes receivable, net........................     1,033             961
  Inventories...............................................        36              42
  Deferred income tax benefit...............................        48              67
  Other.....................................................       242             218
                                                                ------          ------
          Total current assets..............................     1,373           1,302
Property, plant, and equipment, net.........................     4,389           3,945
Notes receivable from EPTPC.................................       626             568
Other.......................................................       448             484
                                                                ------          ------
          Total assets......................................    $6,836          $6,299
                                                                ======          ======
LIABILITIES AND STOCKHOLDER'S EQUITY
Current liabilities
  Accounts payable..........................................    $  673          $  578
  Short-term borrowings (including current maturities of
     long-term debt)........................................        15              15
  Note payable to EPG.......................................       125             170
  Accrual for regulatory issues.............................        --             167
  Other.....................................................       512             349
                                                                ------          ------
          Total current liabilities.........................     1,325           1,279
                                                                ------          ------
Long-term debt, less current maturities.....................       984           1,005
                                                                ------          ------
Deferred income taxes.......................................     1,023             774
                                                                ------          ------
Other.......................................................       688             616
                                                                ------          ------
Commitments and contingencies (See Note 2)
 
Stockholder's equity
  Common stock, par value $5 per share; authorized 300
     shares; issued 208 shares..............................        --              --
  Additional paid-in capital................................     2,740           2,625
  Retained earnings.........................................        76              --
                                                                ------          ------
          Total stockholder's equity........................     2,816           2,625
                                                                ------          ------
          Total liabilities and stockholder's equity........    $6,836          $6,299
                                                                ======          ======
</TABLE>
 
 The accompanying Notes are an integral part of these Consolidated and Combined
                             Financial Statements.
 
                                        2
<PAGE>   5
 
                         TENNESSEE GAS PIPELINE COMPANY
 
               CONSOLIDATED AND COMBINED STATEMENTS OF CASH FLOWS
                                 (IN MILLIONS)
                                  (UNAUDITED)
 
<TABLE>
<CAPTION>
                                                                          SIX MONTHS
                                                                        ENDED JUNE 30,
                                                              ----------------------------------
                                                                    1997              1996
                                                              ----------------   ---------------
                                                              POST-ACQUISITION   PRE-ACQUISITION
                                                                CONSOLIDATED        COMBINED
<S>                                                           <C>                <C>
Cash flows from operating activities
  Net income................................................       $   77             $  79
  Adjustments to reconcile net income to net cash from
     operating activities
     Depreciation, depletion, and amortization..............           77                79
     Net gain on sale of assets.............................           --               (10)
     Deferred income tax expense............................          185                26
     Working capital changes................................          (78)              388
     Other..................................................          (33)               (6)
                                                                  -------             -----
          Net cash provided by operating activities.........          228               556
                                                                  -------             -----
Cash flows from investing activities
  Capital expenditures......................................          (31)             (164)
  Investment in equity securities...........................          (42)               --
  Increase in cash funding to EPG/EPTPC.....................         (165)               --
  Collection of note receivable from partnership............           53                --
  Net proceeds from disposal of businesses and assets.......            1               278
  Other.....................................................            6                (8)
                                                                  -------             -----
          Net cash provided by (used in) investing
             activities.....................................         (178)              106
                                                                  -------             -----
Cash flows from financing activities
  Net proceeds from long-term debt issuance.................          883                --
  Retirement of "push down" acquisition debt................         (883)               --
  Repayment of note payable to EPG..........................          (45)               --
  Retirement of long-term debt..............................           --              (250)
  Net increase in capitalized notes and advances with
     affiliates.............................................           --              (615)
  Net cash contribution from affiliates.....................           --               (17)
  Other.....................................................           (5)                2
                                                                  -------             -----
          Net cash used in financing activities.............          (50)             (880)
                                                                  -------             -----
Increase (decrease) in cash and temporary investments.......           --              (218)
Cash and temporary investments
          Beginning of period...............................           14               305
                                                                  -------             -----
          End of period.....................................       $   14             $  87
                                                                  =======             =====
</TABLE>
 
 The accompanying Notes are an integral part of these Consolidated and Combined
                             Financial Statements.
 
                                        3
<PAGE>   6
 
                         TENNESSEE GAS PIPELINE COMPANY
 
            NOTES TO CONSOLIDATED AND COMBINED FINANCIAL STATEMENTS
                                  (UNAUDITED)
 
1. BASIS OF PRESENTATION AND ACCOUNTING POLICIES
 
     The 1996 Annual Report on Form 10-K for the Company includes a summary of
significant accounting policies and other disclosures and should be read in
conjunction with this Form 10-Q. The condensed consolidated and combined
financial statements at June 30, 1997, and for the six months and quarters ended
June 30, 1997, and 1996, are unaudited. The condensed consolidated balance sheet
at December 31, 1996, is derived from audited financial statements. The Company
has restated its historical financial statements for the six months and quarter
ended June 30, 1996, to reflect the Distributions. These financial statements do
not include all disclosures required by generally accepted accounting
principles. In the opinion of management, all material adjustments necessary to
present fairly the results of operations for such periods have been included.
All such adjustments are of a normal recurring nature. Results of operations for
any interim period are not necessarily indicative of the results of operations
for the entire year due to the cyclical nature of the Company's businesses.
Financial statements for the previous periods include certain reclassifications
which were made to conform to current presentation. Such reclassifications have
no effect on reported net income or stockholders' equity.
 
  Derivative Financial Instruments
 
     The Company utilizes derivative financial instruments to manage price risks
associated with certain energy commodities and interest and foreign currency
exchange rates. In its price risk management activities, the Company engages in
both trading and non-trading activities. The financial instruments used include
swap agreements, futures, options and hedge contracts.
 
     Activities for trading purposes generally consist of services provided to
the energy sector and are accounted for using the mark-to-market method. Such
trading activities are conducted through a variety of financial instruments,
including forward contracts involving cash settlements or physical delivery of
an energy commodity, swap contracts which require payments to (or receipt of
payments from) counterparties based on the differential between a fixed and
variable price for the commodity, options, and other contractual arrangements.
 
     Under mark-to-market accounting, financial instruments with third parties
are reflected at estimated market value, with resulting unrealized gains and
losses recorded in operating income in the Consolidated Statements of Income.
The net gains or losses recognized in the current period result primarily from
transactions originating within the period and the impact of price movements on
transactions originating in previous periods. The assets and liabilities
resulting from mark-to-market accounting are presented as other current assets
and other current liabilities in the Consolidated Balance Sheets. Terms
regarding cash settlement of the contracts vary with respect to the actual
timing of cash receipts and payments. Receivables and payables resulting from
these timing differences are presented in accounts and notes receivable, net,
and accounts payable in the Consolidated Balance Sheets. Cash inflows and
outflows associated with these price risk management activities are recognized
in operating cash flow as the settlement of transactions occur.
 
     The market prices used to value these financial instruments reflect
management's best estimate considering various factors including exchange and
over-the-counter quotations, time value and volatility factors underlying the
commitments. The values are adjusted to reflect the potential impact of
liquidating the Company's position in an orderly manner over a reasonable period
of time under present market conditions.
 
     Activities for non-trading purposes consist of transactions entered into by
the Company to hedge the impact of market fluctuations on assets, liabilities,
production, or other contractual commitments. In order to meet the requirements
of a hedge, the transactions must be designated as a hedge, meet certain
correlation criteria, and reduce price risk. The Company uses forwards, swaps,
and other contracts to hedge the impact of market fluctuations. Changes in the
market value of these financial instruments are deferred until the gains or
 
                                        4
<PAGE>   7
 
losses on the hedged item are recognized. Cash inflows and outflows are
recognized in operating cash flow as the settlement of transactions occurs. Upon
maturity, the gain or loss on derivatives designated as a hedge is recognized
when the underlying transaction gain or loss is recognized. When the underlying
asset being hedged is sold, deferred gains or losses are recognized at the time
of the sale of the underlying asset. Deferred gains or losses are also
recognized at the time it becomes probable that an anticipated transaction or a
portion thereof will not occur.
 
2. COMMITMENTS AND CONTINGENCIES
 
  Rates and Regulatory Matters
 
     In February 1997, TGP filed with FERC a settlement of all issues related to
the recovery by TGP of its GSR and other transition costs and related
proceedings (the "GSR Stipulation and Agreement"). On April 16, 1997, FERC
approved the settlement and TGP implemented the settlement on May 1, 1997. Under
the terms of the GSR Stipulation and Agreement, TGP will be entitled to collect
from customers a total of up to $770 million, of which approximately $647
million has been collected as of June 30, 1997. TGP is entitled to recover
additional transition costs, up to the remaining $123 million, through a demand
transportation surcharge and an interruptible transportation surcharge. The
demand transportation surcharge portion is scheduled to be recovered over a
period extending through December 1998. There is no time limit for collection of
the interruptible transportation surcharge portion. The terms of the GSR
Stipulation and Agreement also provides for a rate case moratorium through
November 2000 (subject to certain limited exceptions) and provides an escalating
rate cap, indexed to inflation, through October 2005, for certain of TGP's
customers.
 
     In January 1995, FERC accepted TGP's rate case which was filed in December
1994, suspended its effectiveness for the maximum period of five months pursuant
to the normal regulatory process, and set the matter for hearing. On July 1,
1995, TGP began collecting rates, subject to refund, reflecting an $87 million
increase in TGP's annual revenue requirement. A stipulation was filed with an
Administrative Law Judge in this proceeding in April 1996. This stipulation
resolves the rates that are the subject of the December 1994 rate case,
including a structural rate design change that results in a larger proportion of
TGP's transportation revenues being dependent upon throughput. In October 1996,
FERC approved the stipulation with certain modifications and clarifications
which are not material. In January 1997, FERC issued an order denying requests
for rehearing of the October 1996 order. Under the stipulation, TGP's refund
obligation was approximately $185 million, inclusive of interest, of which $161
million was refunded to customers in March and June 1997 with the remaining $24
million refund obligation offset against GSR recoveries in accordance with
particular customer elections. TGP had provided a reserve for these rate refunds
as revenues were collected. One party to the rate proceeding, a competitor of
TGP, filed with the Court of Appeals a Petition for Review of the FERC orders
approving the stipulation. The Company believes the FERC orders will be upheld.
 
     In July 1997, FERC issued an order on rehearing of its July 1996 order
addressing cost allocation and rate design issues of TGP's 1991 general rate
proceeding. All cost of service issues were previously resolved pursuant to a
settlement that was approved by FERC. In the July 1996 order, FERC remanded to
the presiding Administrative Law Judge the issue of proper allocation of TGP's
New England lateral costs. In the July 1997 order on rehearing, FERC clarified
among other things, that although the ultimate resolution as to the proper
allocation of costs will be applied retroactively to July 1, 1995, the cost of
service settlement does not allow TGP to recover from other customers amounts
that TGP may ultimately be required to refund. TGP will seek rehearing of this
order. Management believes that the resolution of this issue will not have a
material impact on the financial position or results of operations of the
Company.
 
  Environmental Matters
 
     As of June 30, 1997, the Company had a reserve of approximately $204
million related to the environmental assessments and remediation activities
discussed below.
 
                                        5
<PAGE>   8
 
     Since 1988, TGP has been engaged in an internal project to identify and
deal with the presence of PCBs and other substances on the United States
Environmental Protection Agency List of Hazardous Substances, at compressor
stations and other facilities operated by both its interstate and intrastate
natural gas pipeline systems. While there are still uncertainties relating to
the ultimate costs which may be incurred, based upon the Company's evaluation
and experience to date, the Company believes that the recorded estimate for the
reserve is adequate.
 
     In May 1995, following negotiations with its customers, TGP filed with FERC
a separate Stipulation and Agreement (the "Environmental Stipulation") that
established a mechanism for recovering a substantial portion of the
environmental costs identified in the internal project. In November 1995, FERC
issued an order approving the Environmental Stipulation. Although one shipper
filed for rehearing, FERC denied rehearing of its order in February 1996. This
shipper filed a Petition of Review in April 1996 in the Court of Appeals; TGP
believes the FERC order approving the Environmental Stipulation will be upheld
on appeal. The Environmental Stipulation was effective July 1, 1995. As of June
30, 1997, a balance of $37 million remains to be collected under this agreement.
 
     The Company and certain of its subsidiaries have been designated, have
received notice that they should be designated, or have been asked for
information to determine whether they should be designated as a PRP with respect
to 27 sites under the Comprehensive Environmental Response, Compensation and
Liability Act (CERCLA or Superfund) or state equivalents. The Company has sought
to resolve its liability as a PRP with respect to these Superfund sites through
indemnification by third parties and/or settlements which provide for the
payment of the Company's allocable share of remediation costs. Because the
clean-up costs are estimates and are subject to revision as more information
becomes available about the extent of remediation required, the Company's
estimate of its share of remediation costs could change. Moreover, liability
under the federal Superfund statute is joint and several, meaning that the
Company could be required to pay in excess of its pro rata share of remediation
costs if other parties are unable to pay. The Company's understanding of the
financial strength of other PRPs has been considered, where appropriate, in its
determination of its estimated liability as described herein. The Company
presently believes that the recorded estimate for the reserve associated with
the Superfund sites is adequate.
 
     In addition, the Company has identified a number of formerly owned or
leased sites, and certain other sites associated with its discontinued
operations, where environmental remediation may be required. The Company
presently believes that the recorded estimate for the reserve associated with
these sites is adequate.
 
  Legal Proceedings
 
     In July 1996, TPG was served with a complaint in the matter of Jack J.
Grynberg v. Alaska Pipeline Co., et al., filed in the U.S. District Court for
the District of Columbia (the "Court"). The plaintiff filed this action under
the False Claims Act against most interstate pipelines and others alleging that
the defendants mismeasured natural gas produced from federal and Indian land,
which deprived the United States of royalties otherwise due it. Among other
things, the plaintiff sought to recover unspecified treble damages on behalf of
the United States. The plaintiff also sought to recover his finder's fee and
attorneys' fees. In response to motions filed by most defendants, the Court, in
March 1997, issued an order dismissing the complaint. TGP cannot predict what
action the plaintiff will take in response to the Court's order. Based on
information available at this time, TGP does not believe that the ultimate
resolution of this matter will have a materially adverse effect on the Company's
financial position or results of operations.
 
     In Commonwealth of Kentucky, Natural Resources and Environmental Protection
Cabinet v. Tennessee Gas Pipeline Company (Franklin County Circuit Court, Docket
No. 88-C1-1531, November 16, 1988), the Kentucky environmental agency alleged
that TGP discharged pollutants into the waters of the state without a permit and
disposed of PCBs without a permit. The agency sought an injunction against
future discharges, sought an order to remediate or remove PCBs, and sought a
civil penalty. TGP has entered into agreed orders with the agency to resolve
many of the issues raised in the original allegations, has received water
discharge permits for its Kentucky stations from the agency, and continues to
work to resolve the remaining issues. Management believes that the resolution of
this issue will not have a materially adverse effect on the Company's financial
position or results of operations.
 
                                        6
<PAGE>   9
 
     The Company is a named defendant in numerous lawsuits and a named party in
numerous governmental proceedings arising in the ordinary course of business.
While the outcome of such lawsuits or other proceedings against the Company
cannot be predicted with certainty, management currently does not expect these
matters to have a materially adverse effect on the Company's financial position
or results of operations.
 
3. FINANCING TRANSACTIONS
 
     In March 1997, TGP closed the sale of $300 million aggregate principal of
7 1/2% debentures due 2017, $300 million aggregate principal of 7% debentures
due 2027, and $300 million aggregate principal of 7 5/8% debentures due 2037.
Proceeds of approximately $883 million, net of issuance costs, were used to
repay a portion of EPTPC's credit facility, pushed down to the TGP financial
statements as a result of the Merger. With this repayment, TGP's acquisition
debt was retired.
 
4. PROPERTY, PLANT, AND EQUIPMENT
 
     Property, plant, and equipment at June 30, 1997, and December 31, 1996,
consisted of the following:
 
<TABLE>
<CAPTION>
                                                               1997      1996
                                                              ------    ------
                                                               (IN MILLIONS)
<S>                                                           <C>       <C>
Property, plant, and equipment, at cost.....................  $2,336    $2,371
Less accumulated depreciation and depletion.................      57        --
                                                              ------    ------
                                                               2,279     2,371
Additional acquisition cost assigned to utility plant, net
  of accumulated amortization...............................   2,110     1,574
                                                              ------    ------
          Total property, plant, and equipment, net.........  $4,389    $3,945
                                                              ======    ======
</TABLE>
 
     The increase in additional acquisition cost assigned to plant is a result
of the Company's continuing efforts to evaluate the fair market value of the
assets and liabilities acquired in conjunction with the Merger.
 
5. INVENTORIES
 
     Inventories at June 30, 1997, and December 31, 1996, consisted of the
following:
 
<TABLE>
<CAPTION>
                                                              1997      1996
                                                              ----      ----
                                                              (IN MILLIONS)
<S>                                                           <C>       <C>
Materials and supplies......................................   $19       $19
Gas in storage..............................................    17        23
                                                               ---       ---
                                                               $36       $42
                                                               ===       ===
</TABLE>
 
     Materials and supplies and gas in storage are valued at the lower of cost
or market, with cost determined using the average cost method.
 
6. ACCOUNTING FOR REGULATED OPERATIONS
 
     The Company's businesses that are subject to the regulations and accounting
requirements of FERC have followed the accounting requirements of SFAS No. 71,
Accounting for the Effects of Certain Types of Regulation, which may differ from
those accounting methods used by non-regulated entities. Changes in the
regulatory and economic environment may, at some point in the future, create
circumstances in which the application of regulatory accounting principles would
no longer be appropriate. During the first quarter of 1997, FERC approved TGP's
GSR Stipulation and Agreement (discussed previously in Rates and Regulatory
Matters of Note 2). The Company is currently evaluating the impact the FERC
approval may have on the continued application of regulatory accounting
principles. If these accounting principles should no longer be applied, an
amount would be charged to earnings as an extraordinary item in accordance with
SFAS No. 101, Regulated Enterprises -- Accounting for Discontinuation of
Application of SFAS No. 71. At June 30, 1997, this amount was estimated to be
approximately $47 million, net of income taxes. Any potential charge would
 
                                        7
<PAGE>   10
 
be non-cash and would not have a direct effect on the regulated companies'
ability to seek recovery of the underlying deferred costs in their future rate
proceedings or on their ability to collect the rates set thereby.
 
7. RECENT PRONOUNCEMENTS
 
  Earnings per share
 
     In March 1997, the Financial Accounting Standards Board issued SFAS No.
128, Earnings Per Share, which establishes new guidelines for calculating
earnings per share. This pronouncement applies only to entities with publicly
held common stock and, therefore, does not apply to TGP.
 
  Capital structure
 
     In March 1997, the Financial Accounting Standards Board issued SFAS No.
129, Disclosure of Information about Capital Structure, which consolidates
capital structure reporting requirements previously required by other accounting
standards. This pronouncement, which will become effective for reporting periods
ending after December 15, 1997, will have no impact on the Company's disclosure
of capital structure information.
 
  Comprehensive Income
 
     In June 1997, the Financial Accounting Standards Board issued SFAS No. 130,
Reporting Comprehensive Income, which establishes standards for reporting and
display of comprehensive income and its components in a full set of
general-purpose financial statements. SFAS No. 130 requires that all items that
are required to be recognized under accounting standards as components of
comprehensive income be reported in a financial statement that is displayed with
the same prominence as other financial statements. This pronouncement is
effective for fiscal years beginning after December 15, 1997. The Company is
currently evaluating the impact of this pronouncement.
 
  Segment Reporting
 
     In June 1997, the Financial Accounting Standards Board issued SFAS No. 131,
Disclosures about Segments of an Enterprise and Related Information, which
establishes the way that public business enterprises report information about
operating segments in annual and interim financial statements issued to
shareholders. It also establishes standards for related disclosures about
products and services, geographic areas, and major customers. This pronouncement
is effective for financial statements for periods beginning after December 15,
1997. The Company is currently evaluating the impact of this pronouncement.
 
  Derivative Disclosure
 
     The Securities and Exchange Commission recently issued Financial Reporting
Release No. 48, Disclosure of Derivative and Other Financial Instruments, which
requires enhanced disclosure related to accounting policies for derivatives and
quantitative and qualitative disclosure concerning market risk inherent in
derivatives and other financial instruments.
 
     The effective date for the enhanced-accounting policy disclosure
requirements is for fiscal periods ending after June 15, 1997 (see Note 1). The
requirements for quantitative and qualitative disclosures about market risks are
effective for the Company for December 31, 1997. The Company is currently
evaluating the impact of this pronouncement.
 
  Other
 
     The Company adopted SFAS No. 125, Accounting for Transfers and Servicing of
Financial Assets and Extinguishment of Liabilities, SFAS No. 127, Deferral of
the Effective Date of Certain Provisions of FASB Statement No. 125, and
Statement of Position No. 96-1, Environmental Remediation Liabilities, effective
 
                                        8
<PAGE>   11
 
January 1, 1997. These pronouncements did not have a material impact on the
Company's financial position or results of operations.
 
ITEM 2. MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS
        OF OPERATIONS
 
     The information contained in Item 2 updates, and should be read in
conjunction with, information set forth in Part II, Items 7 and 8, in the
Company's Annual Report on Form 10-K for the year ended December 31, 1996, in
addition to the interim consolidated financial statements and accompanying notes
presented in Item 1 of this Form 10-Q.
 
                             RESULTS OF OPERATIONS
 
REGULATED OPERATIONS
 
<TABLE>
<CAPTION>
                                      SECOND QUARTER                           SIX MONTHS
                            -----------------------------------    -----------------------------------
                                  1997               1996                1997               1996
                            ----------------    ---------------    ----------------    ---------------
       (IN MILLIONS)        POST-ACQUISITION    PRE-ACQUISITION    POST-ACQUISITION    PRE-ACQUISITION
       -------------          CONSOLIDATED         COMBINED          CONSOLIDATED         COMBINED
<S>                         <C>                 <C>                <C>                 <C>
Operating revenues.........       $189               $187                $404               $400
Operating expenses.........        117                138                 252                280
                                ------               ----              ------               ----
Operating income...........       $ 72               $ 49                $152               $120
                                ======               ====              ======               ====
</TABLE>
 
  Second Quarter 1997 Compared to Second Quarter 1996
 
     Operating revenues for the quarter ended June 30, 1997, were $2 million
higher than for the same period of 1996. The increase was primarily due to new
system rates on TGP which went into effect November 1, 1996.
 
     Operating expenses for the quarter ended June 30, 1997, were $21 million
lower than for the same period of 1996, primarily due to lower labor and benefit
costs attributable to a reduction in staffing levels which occurred throughout
the latter half of 1996 and the first quarter of 1997, as well as lower legal
costs and operating and maintenance costs. The decrease in operating expenses
was partially offset by an increase in depreciation expense as a result of the
amortization of additional acquisition cost assigned to utility plant.
 
  Six Months Ended 1997 Compared to Six Months Ended 1996
 
     Operating revenues for the six months ended June 30, 1997, were $4 million
higher than for the same period of 1996. The increase was primarily due to new
system rates on TGP which went into effect November 1, 1996.
 
     Operating expenses for the six months ended June 30, 1997, were $28 million
lower than for the same period of 1996, primarily due to lower labor and benefit
costs attributable to a reduction in staffing levels which occurred throughout
the latter half of 1996 and the first quarter of 1997, as well as lower legal
costs and operating and maintenance costs. The decrease in operating expenses
was partially offset by an increase in depreciation expense as a result of the
amortization of additional acquisition cost assigned to utility plant.
 
                                        9
<PAGE>   12
 
NON-REGULATED OPERATIONS
 
<TABLE>
<CAPTION>
                                      SECOND QUARTER                           SIX MONTHS
                            -----------------------------------    -----------------------------------
                                  1997               1996                1997               1996
                            ----------------    ---------------    ----------------    ---------------
       (IN MILLIONS)        POST-ACQUISITION    PRE-ACQUISITION    POST-ACQUISITION    PRE-ACQUISITION
       -------------          CONSOLIDATED         COMBINED          CONSOLIDATED         COMBINED
<S>                         <C>                 <C>                <C>                 <C>
Gathering and treating
  margin...................       $  2               $  2                $  4               $  5
Processing margin..........         --                 --                   3                  1
Marketing margin...........         (1)                 3                   7                 11
Other......................          2                 35                   2                 77
                                ------               ----              ------               ----
          Total gross
            margin.........          3                 40                  16                 94
Operating expenses.........         23                 53                  40                115
                                ------               ----              ------               ----
Operating loss.............       $(20)              $(13)               $(24)              $(21)
                                ======               ====              ======               ====
</TABLE>
 
  Second Quarter 1997 Compared to Second Quarter 1996
 
     Total gross margin (revenue less cost of sales) and operating expenses were
both lower for the quarter ended June 30, 1997, than for the same period of 1996
primarily due to the discontinuance of Tenneco Credit Corporation (now renamed
El Paso Energy Credit Corporation) commercial activities and the sale of certain
businesses in the fourth quarter of 1996. These sales included the Company's oil
and gas exploration, production and financing unit, formerly known as Tenneco
Ventures, and 70 percent of the Company's interests in two natural gas pipeline
systems in Australia. Following the sale, the Australian natural gas pipelines
operations were accounted for by the equity method. As part of the continuing
effort to integrate the businesses of EPG and the Company subsequent to the
Merger, substantially all the marketing business of EPG's marketing subsidiaries
was transferred to the Company's marketing subsidiaries effective April 1, 1997.
The marketing margin loss is associated with generally lower industry-wide gas
marketing margins.
 
  Six Months Ended 1997 Compared to Six Months Ended 1996
 
     Total gross margin and operating expenses were both lower for the six
months ended June 30, 1997, than for the same period of 1996 primarily due to
the discontinuance of Tenneco Credit Corporation
(now renamed El Paso Energy Credit Corporation) commercial activities and the
sale of certain businesses in the fourth quarter of 1996. These sales included
the Company's oil and gas exploration, production and financing unit, formerly
known as Tenneco Ventures, and 70 percent of the Company's interests in two
natural gas pipeline systems in Australia. Following the sale, the Australian
natural gas pipelines operations were accounted for by the equity method. The
decrease in marketing margins is associated with lower industry-wide gas
marketing margins in the second quarter of 1997, as well as extreme market
volatility which negatively impacted natural gas marketing activities and
trading positions during the first quarter.
 
OTHER INCOME AND EXPENSE
 
  Second Quarter 1997 Compared to Second Quarter 1996
 
     Other expense for the quarter ended June 30, 1997, was $29 million higher
than for the same period of 1996. The increase was due primarily to a favorable
legal settlement in the second quarter of 1996.
 
  Six Months Ended 1997 Compared to Six Months Ended 1996
 
     Other expense for the six months ended June 30, 1997, was $33 million
higher than for the same period of 1996. The increase was due primarily to the
recognition of a gain on the sale of the Company's 50 percent general
partnership interest in Tenneco Mobile Bay Gathering Co. in February 1996, a
reduction in equity income from unconsolidated subsidiaries, a favorable legal
settlement in the second quarter of 1996, and a reduction of other income in
1997, partially offset by an increase in affiliated interest income in 1997.
 
                                       10
<PAGE>   13
 
      CAUTIONARY STATEMENT FOR PURPOSES OF THE "SAFE HARBOR" PROVISIONS OF
              THE PRIVATE SECURITIES LITIGATION REFORM ACT OF 1995
 
     This report contains forward-looking statements within the meaning of the
Private Securities Litigation Reform Act of 1995. Where any such forward-looking
statement includes a statement of the assumptions or bases underlying such
forward-looking statement, the Company cautions that, while such assumptions or
bases are believed to be reasonable and are made in good faith, assumed facts or
bases almost always vary from the actual results, and the differences between
assumed facts or bases and actual results can be material, depending upon the
circumstances. Where, in any forward-looking statement, the Company or its
management expresses an expectation or belief as to future results, such
expectation or belief is expressed in good faith and is believed to have a
reasonable basis, but there can be no assurance that the statement of
expectation or belief will result or be achieved or accomplished. The words
"believe," "expect," "estimate," "anticipate" and similar expressions may
identify forward-looking statements.
 
     Taking into account the foregoing, the following are identified as
important factors that could cause actual results to differ materially from
those expressed in any forward-looking statement made by, or on behalf of, the
Company:
 
  Highly Competitive Industry
 
     The ability to maintain or increase current transmission, gathering,
processing, and sales volumes, or to remarket unsubscribed capacity, can be
subject to the impact of future weather conditions, including those that favor
other alternative energy sources; price competition; drilling activity and
supply availability; and service competition. Future profitability also may be
affected by the Company's ability to compete with the services offered by other
energy enterprises which may be larger, offer more services, and possess greater
resources. The ability of TGP to negotiate new contracts and to renegotiate
existing contracts (70 percent of which are expiring over the next four years,
principally in November 2000) could be adversely affected by the proposed
construction by other parties of additional pipeline capacity in the Northeast
U.S., the viability of the Company's expansion projects reduced demand due to
higher gas prices, the availability of alternative energy sources, and other
factors that are not within its control.
 
  Impact of Natural Gas and Natural Gas Liquids Prices
 
     The value of natural gas transmission services is based on an all-in cost,
including the cost of the natural gas. Therefore, the Company's ability to
compete with other transporters is impacted by natural gas prices in the supply
basins connected to its pipeline systems compared to prices in other gas
producing regions, especially Canada. Additionally, revenues generated by the
Company from its gathering and processing contracts are dependent upon volumes
and rates, both of which can be affected by the prices of natural gas and
natural gas liquids. Fluctuations in energy prices are caused by a number of
factors, including regional, domestic and international demand, availability and
adequacy of transportation facilities, energy legislation, federal or state
taxes, if any, on the sale or transportation of natural gas and natural gas
liquids and the price and abundance of supplies of alternative energy sources.
 
  Use of Derivative Financial Instruments
 
     In the ordinary course and conduct of its business, some of the Company's
non-regulated subsidiaries are engaged in the gathering, processing and
marketing of natural gas and other energy commodities and utilize futures and
option contracts traded on the New York Mercantile Exchange and over-the-counter
options and price and basis swaps with other gas merchants and financial
institutions. The Company could incur financial losses in future periods as a
result of volatility in the market values of the underlying commodities or if
one of its counterparties fails to perform under a contract.
 
  Acquisitions and Investments
 
     Opportunities for growth through acquisitions and investments in joint
ventures and the future operating results and success of such acquisitions and
joint ventures within and outside the U.S. may be subject to the
 
                                       11
<PAGE>   14
 
effects of, and changes in, U.S. and foreign trade and monetary policies, laws
and regulations, political and economic developments, inflation rates, and the
effects of taxes and operating conditions. Activities in areas outside the U.S.
also are subject to the risks inherent in foreign operations, including loss of
revenue, property and equipment as a result of hazards such as expropriation,
nationalization, wars, insurrection and other political risks, and the effects
of currency fluctuations and exchange controls. Such legal and regulatory delays
and other unforeseeable obstacles may be beyond the Company's control or ability
to manage.
 
  Potential Environmental Liabilities
 
     The Company 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, regulation and
enforcement polices thereunder, and claims for damages to property, employees,
other persons and the environment resulting from current or discontinued
operations, could result in substantial costs and liabilities in the future.
 
  Operating Hazards and Uninsured Risks
 
     While the Company maintains insurance against certain of the risks normally
associated with the transportation, gathering and processing of natural gas,
including explosions, pollution and fires, the occurrence of a significant event
that is not fully insured against could have a material adverse effect on the
Company.
 
  Potential Liabilities Related to the Merger
 
     The amount of the actual and contingent liabilities of EPTPC, which
remained the liabilities of the Company after the Merger, could vary materially
from the amount estimated by the Company, which was based upon assumptions which
could prove to be inaccurate. If New Tenneco or Newport News Shipbuilding Inc.
were unable or unwilling to pay their respective liabilities, a court could
require the Company, under certain legal theories which may or may not be
applicable to the situation, to assume responsibility for such obligations,
which could have a material adverse effect on the Company.
 
  Uncertainty Surrounding Integration of Operations
 
     The Company has begun to integrate the business and operations of EPTPC and
its subsidiaries to increase operating and administrative efficiency through
consolidation and reengineering of facilities, workforce reductions and
coordination of purchasing, sales and marketing activities. Management
anticipates that the complementary interstate and intrastate pipeline operations
and energy marketing activities of the combined company should provide increased
operating flexibility and access to additional customers and markets, although
the amount and timing of the realization of such benefits will depend upon the
Company's ability to integrate successfully the businesses and operations of the
companies, and the time period over which such integration is effected.
 
  Potential Federal Income Tax Liabilities
 
     In connection with the Merger and Distributions, the Internal Revenue
Service issued a private letter ruling to Old Tenneco, in which the Internal
Revenue Service ruled that for U.S. federal income tax purposes (i) the
Distributions would be tax-free to Old Tenneco and, except to the extent cash
was received in lieu of fractional shares, to its then existing stockholders,
(ii) the Merger would constitute a tax-free reorganization, and (iii) that
certain other transactions effected in connection with the Merger and
Distributions would be tax-free. If the Distributions were not to qualify as
tax-free distributions, then a corporate level federal income tax would be
assessed to the consolidated group of which Old Tenneco was the common parent.
This corporate level federal income tax would be payable by EPTPC. Under certain
limited circumstances, however, New Tenneco and Newport News Shipbuilding Inc.
have agreed to indemnify EPTPC for a defined portion of such tax liabilities.
 
                                       12
<PAGE>   15
 
  Refinancing and Interest Rate Exposure Risks
 
     The business and operating results of the Company can be adversely affected
by factors such as the availability or cost of capital, changes in interest
rates, changes in the tax rates due to new tax laws, market perceptions of the
natural gas industry or the Company, or credit ratings.
 
  Potential for Changes in Accounting Standards
 
     Authoritative generally accepted accounting principles or policy changes
from such standard setting bodies as the Financial Accounting Standards Board,
FERC, and the Securities and Exchange Commission may affect the Company's
results of operations or financial position.
 
                                       13
<PAGE>   16
 
                          PART II -- OTHER INFORMATION
 
ITEM 1. LEGAL PROCEEDINGS
 
     See Part I, Financial Information, Note 2, which is incorporated herein by
reference.
 
ITEM 2. CHANGES IN SECURITIES
 
     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, TGP, hereby undertakes, pursuant to Regulation S-K,
     Item 601(b),
     paragraph (4)(iii), to furnish to the Securities and Exchange Commission
     upon request all constituent instruments defining the rights of holders of
     long-term debt of TGP 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 TGP and its consolidated subsidiaries.
 
b. Reports on Form 8-K
 
     None.
 
                                       14
<PAGE>   17
 
                                   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 13, 1997                              /s/ H. BRENT AUSTIN
                                            ------------------------------------
                                                      H. Brent Austin
                                                  Executive Vice President
 
Date: August 13, 1997                             /s/ JEFFREY I. BEASON
                                            ------------------------------------
                                                     Jeffrey I. Beason
                                               Vice President and Controller
 
                                       15
<PAGE>   18
 
                               INDEX TO EXHIBITS
 
<TABLE>
<CAPTION>
        EXHIBIT
         NUMBER
        -------
<C>                       <S>
           27             Financial Data Schedule
</TABLE>