<PAGE>


                                    FORM 10-Q


                       SECURITIES AND EXCHANGE COMMISSION

                             Washington, D.C. 20549


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

                For the quarterly period ended September 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 33-15998-06


                          SWIFT ENERGY MANAGED PENSION
                         ASSETS PARTNERSHIP 1989-C, LTD.
             (Exact name of registrant as specified in its charter)

<TABLE>
<S>                                           <C>
                  Texas                                   76-0281859
(State or other jurisdiction of organization) (I.R.S. Employer Identification No.)
</TABLE>


                        16825 Northchase Drive, Suite 400
                              Houston, Texas 77060
                    (Address of principal executive offices)
                                   (Zip Code)

                                  (281)874-2700
              (Registrant's telephone number, including area code)

                                      None
              (Former name, former address and former fiscal year,
                          if changed since last report)


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
   ----       ----



<PAGE>

                          SWIFT ENERGY MANAGED PENSION
                         ASSETS PARTNERSHIP 1989-C, LTD.

                                      INDEX



<TABLE>
<CAPTION>
PART I.    FINANCIAL INFORMATION                                                     PAGE
<S>                                                                                  <C>
ITEM 1.    Financial Statements

      Balance Sheets

          - September 30, 1997 and December 31, 1996                                  3

      Statements of Operations

          - Three month and nine month periods ended September 30, 1997 and 1996      4

      Statements of Cash Flows

          - Nine month periods ended September 30, 1997 and 1996                      5

      Notes to Financial Statements                                                   6

ITEM 2.    Management's Discussion and Analysis of Financial
               Condition and Results of Operations                                    9

PART II.    OTHER INFORMATION                                                        11


SIGNATURES                                                                           12
</TABLE>



<PAGE>

                          SWIFT ENERGY MANAGED PENSION
                         ASSETS PARTNERSHIP 1989-C, LTD.
                                 BALANCE SHEETS



<TABLE>
<CAPTION>
                                                                                        September 30,        December 31,
                                                                                            1997                 1996
                                                                                       ---------------     ----------------
                                                                                        (Unaudited)
         <S>                                                                           <C>                  <C>           
         ASSETS:

         Current Assets:
              Cash and cash equivalents                                                $      262,339       $      166,985
              Nonoperating interests income receivable                                         77,117              320,324
                                                                                       ---------------     ----------------
                   Total Current Assets                                                       339,456              487,309
                                                                                       ---------------     ----------------
         Nonoperating interests in oil and gas
              properties, using full cost accounting                                        2,307,223            2,295,768
         Less-Accumulated amortization                                                     (1,955,180)          (1,907,029)
                                                                                       ---------------     ----------------
                                                                                              352,043              388,739
                                                                                       ---------------     ----------------
                                                                                       $      691,499       $      876,048
                                                                                       ===============     ================


         LIABILITIES AND PARTNERS' CAPITAL:

         Current Liabilities:
              Payable related to excess costs                                          $        3,368       $        3,325
                                                                                       ---------------     ----------------

         Partners' Capital                                                                    688,131              872,723
                                                                                       ---------------     ----------------
                                                                                       $      691,499       $      876,048
                                                                                       ===============     ================
</TABLE>



                 See accompanying notes to financial statements.

                                        3


<PAGE>

                          SWIFT ENERGY MANAGED PENSION
                         ASSETS PARTNERSHIP 1989-C, LTD.
                            STATEMENTS OF OPERATIONS
                                   (Unaudited)




<TABLE>
<CAPTION>
                                                     Three Months Ended                   Nine Months Ended
                                                        September 30,                      September 30,
                                              ---------------------------------  ---------------------------------
                                                   1997               1996             1997             1996
                                              ---------------   ---------------  ---------------   ---------------
<S>                                           <C>               <C>              <C>               <C>            
REVENUES:
   Income from nonoperating interests         $        43,655   $        51,163  $       155,042   $       260,622
   Interest income                                      3,585               472            9,585               540
                                              ---------------   ---------------  ---------------   ---------------
                                                       47,240            51,635          164,627           261,162
                                              ---------------   ---------------  ---------------   ---------------

COSTS AND EXPENSES:
   Amortization                                        15,278            30,559           48,151           105,123
   General and administrative                          10,105            14,249           38,946            42,851
                                              ---------------   ---------------  ---------------   ---------------
                                                       25,383            44,808           87,097           147,974
                                              ---------------   ---------------  ---------------   ---------------
NET INCOME (LOSS)                             $        21,857   $         6,827  $        77,530   $       113,188
                                              ===============   ===============  ===============   ===============



Limited Partners' net income (loss)
   per unit                                   $           .80   $           .25  $          2.83   $          4.14
                                              ===============   ===============  ===============   ===============
</TABLE>



                 See accompanying notes to financial statements.

                                        4


<PAGE>

                          SWIFT ENERGY MANAGED PENSION
                         ASSETS PARTNERSHIP 1989-C, LTD.
                            STATEMENTS OF CASH FLOWS
                                   (Unaudited)

<TABLE>
<CAPTION>
                                                                                           Nine Months Ended
                                                                                             September 30,
                                                                               ----------------------------------------
                                                                                     1997                    1996
                                                                               ---------------          ---------------
<S>                                                                             <C>                     <C>            
CASH FLOWS FROM OPERATING ACTIVITIES:
    Income (Loss)                                                               $       77,530          $       113,188
    Adjustments to reconcile income (loss) to
      net cash provided by operations:
      Amortization                                                                      48,151                  105,123
      Change in assets and liabilities:
        (Increase) decrease in nonoperating interests income receivable                 32,478                  (28,911)
        (Increase) decrease in other current assets                                    210,729                       --
        Increase (decrease) in accounts payable
          and accrued liabilities                                                           --                  (66,510)
                                                                               ---------------          ---------------
               Net cash provided by (used in) operating activities                     368,888                  122,890
                                                                               ---------------          ---------------
CASH FLOWS FROM INVESTING ACTIVITIES:
    Additions to nonoperating interests in oil and gas properties                      (11,455)                 (12,271)
    Proceeds from sale of nonoperating interests
      in oil and gas properties                                                             --                  101,843
    Increase (decrease) in payable related to excess costs                                  43                       --
                                                                               ---------------          ---------------
               Net cash provided by (used in) investing activities                     (11,412)                  89,572
                                                                               ---------------          ---------------
CASH FLOWS FROM FINANCING ACTIVITIES:
    Cash distributions to partners                                                    (262,122)                (140,805)
                                                                               ---------------          ---------------
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS                                    95,354                   71,657
                                                                               ---------------          ---------------
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD                                       166,985                    1,284
                                                                               ---------------          ---------------
CASH AND CASH EQUIVALENTS AT END OF PERIOD                                      $      262,339          $        72,941
                                                                               ===============          ===============
Supplemental disclosure of cash flow information:
    Cash paid during the period for interest                                    $           --          $           312
                                                                               ===============          ===============
</TABLE>



                 See accompanying notes to financial statements.

                                        5


<PAGE>

                          SWIFT ENERGY MANAGED PENSION
                         ASSETS PARTNERSHIP 1989-C, LTD.
                          NOTES TO FINANCIAL STATEMENTS
                                   (UNAUDITED)


(1)  General Information -

                  The financial statements included herein have been prepared by
        the  Partnership  and are  unaudited  except  for the  balance  sheet at
        December  31,  1996  which has been  taken  from the  audited  financial
        statements at that date. The financial  statements reflect  adjustments,
        all of which  were of a  normal  recurring  nature,  which  are,  in the
        opinion  of  the  managing   general   partner   necessary  for  a  fair
        presentation.  Certain  information  and footnote  disclosures  normally
        included in financial  statements  prepared in accordance with generally
        accepted  accounting  principles have been omitted pursuant to the rules
        and regulations of the Securities and Exchange Commission  ("SEC").  The
        Partnership  believes adequate disclosure is provided by the information
        presented.  The financial  statements should be read in conjunction with
        the audited  financial  statements  and the notes included in the latest
        Form 10-K.

(2)  Organization and Terms of Partnership Agreement -

                  Swift Energy Managed Pension Assets Partnership 1989-C,  Ltd.,
        a Texas limited partnership ("the Partnership"), was formed on September
        30,  1989,  for  the  purpose  of  purchasing  net  profits   interests,
        overriding  royalty  interests  and  royalty  interests   (collectively,
        "nonoperating interests") in producing oil and gas properties within the
        continental  United  States.  Swift Energy  Company  ("Swift"),  a Texas
        corporation,  and VJM  Corporation  ("VJM"),  a California  corporation,
        serve as Managing  General  Partner and Special  General  Partner of the
        Partnership,   respectively.   The  general  partners  are  required  to
        contribute up to 1/99th of limited  partner net  contributions.  The 322
        limited partners made total capital contributions of $2,735,300.

                  Nonoperating  interests  acquisition  costs and the management
        fee are borne 99 percent by the limited  partners and one percent by the
        general  partners.  Organization and syndication costs were borne solely
        by the limited partners.

                  Generally,  all continuing costs (including development costs,
        operating costs,  general and  administrative  reimbursements and direct
        expenses) and revenues are allocated 90 percent to the limited  partners
        and ten percent to the general partners. If prior to partnership payout,
        however,  the cash  distribution  rate for a  certain  period  equals or
        exceeds  17.5  percent,  then for the  following  calendar  year,  these
        continuing  costs and  revenues  will be  allocated  85  percent  to the
        limited  partners  and  15  percent  to  the  general  partners.   After
        partnership  payout,  continuing  costs and  revenues  will be shared 85
        percent by the limited partners, and 15 percent by the general partners,
        even if the cash  distribution  rate is less than 17.5  percent.  During
        1992 and 1991, the cash distribution rate (as defined in the Partnership
        Agreement)  exceeded  17.5  percent  and  thus,  in 1993 and  1992,  the
        continuing  costs and  revenues  were  shared 85 percent by the  limited
        partners and 15 percent by the general partners. During 1996, 1995, 1994
        and 1993, the cash  distribution  rate fell below 17.5 percent and thus,
        in 1997,  1996, 1995 and 1994, the continuing costs and revenues will be
        (were)  shared 90 percent by the limited  partners and 10 percent by the
        general partners.

(3)  Significant Accounting Policies -

      Use of Estimates --

                  The  preparation  of financial  statements in conformity  with
        generally accepted  accounting  principles  requires  management to make
        estimates and assumptions that affect the reported amounts of assets and
        liabilities  at the date of the  financial  statements  and the reported
        amounts of revenues and expenses  during the  reporting  period.  Actual
        results could differ from estimates. Certain reclassifications have been
        made to prior year amounts to conform to the current year presentation.


                                       6


<PAGE>

                          SWIFT ENERGY MANAGED PENSION
                         ASSETS PARTNERSHIP 1989-C, LTD.
                    NOTES TO FINANCIAL STATEMENTS (CONTINUED)
                                   (UNAUDITED)


     Nonoperating Interests in Oil and Gas Properties --

                  For financial  reporting purposes the Partnership  follows the
        "full-cost"  method of accounting for nonoperating  interests in oil and
        gas property costs. Under this method of accounting,  all costs incurred
        in the acquisition of  nonoperating  interests in oil and gas properties
        are capitalized.  The unamortized cost of nonoperating  interests in oil
        and gas  properties is limited to the "ceiling  limitation"  (calculated
        separately for the Partnership,  limited partners and general partners).
        The  "ceiling  limitation"  is  calculated  on  a  quarterly  basis  and
        represents the estimated future net revenues from nonoperating interests
        in proved  properties  using current  prices  discounted at ten percent.
        Proceeds from the sale or disposition of  nonoperating  interests in oil
        and  gas  properties  are  treated  as a  reduction  of the  cost of the
        nonoperating  interests  with no gains or  losses  recognized  except in
        significant transactions.

                  The Partnership computes the provision for amortization of oil
        and gas properties on the units-of-production method. Under this method,
        the provision is calculated by multiplying the total unamortized cost of
        oil and gas  properties  by an overall rate  determined  by dividing the
        physical  units of oil and gas  produced  during the period by the total
        estimated proved oil and gas reserves at the beginning of the period.

                  The calculation of the "ceiling  limitation" and the provision
        for  depreciation,  depletion and  amortization is based on estimates of
        proved reserves. There are numerous uncertainties inherent in estimating
        quantities  of proved  reserves  and in  projecting  the future rates of
        production,  timing and plan of development. The accuracy of any reserve
        estimate  is a  function  of  the  quality  of  available  data  and  of
        engineering  and  geological  interpretation  and  judgment.  Results of
        drilling,  testing and production subsequent to the date of the estimate
        may justify revision of such estimate.  Accordingly,  reserve  estimates
        are  often  different  from  the  quantities  of oil  and gas  that  are
        ultimately recovered.

(4)  Related-Party Transactions -

                  An  affiliate  of  the  Special  General  Partner,  as  Dealer
        Manager,  received  $68,383 for managing and  overseeing the offering of
        the limited  partnership units. A one-time management fee of $68,383 was
        paid to Swift for services performed for the Partnership.

                  The  Partnership  entered  into a Net Profits  and  Overriding
        Royalty Interests Agreement ("NP/OR Agreement") with Swift Energy Income
        Partners 1989-C, Ltd. ("Operating  Partnership"),  managed by Swift, for
        the purpose of acquiring nonoperating interests in producing oil and gas
        properties.   Under  terms  of  the  NP/OR   Agreement,   the  Operating
        Partnership will convey to the Partnership nonoperating interests in the
        aggregate net profits (i.e., oil and gas sales net of related  operating
        costs) of the properties  acquired equal to its  proportionate  share of
        the property acquisition costs.

(5)  Vulnerability Due to Certain Concentrations -

                  The  Company's  revenues are  primarily the result of sales of
         its oil and natural gas  production.  Market  prices of oil and natural
         gas may fluctuate and adversely affect operating results.

                  The Partnership extends credit to various companies in the oil
         and gas industry which results in a concentration  of credit risk. This
         concentration  of credit risk may be affected by changes in economic or
         other conditions and may accordingly  impact the Partnership's  overall
         credit risk.  However,  the Managing  General Partner believes that the
         risk is mitigated by the size, reputation,  and nature of the companies
         to which the Partnership  extends credit. In addition,  the Partnership
         generally  does not  require  collateral  or other  security to support
         customer receivables.


                                       7


<PAGE>

                          SWIFT ENERGY MANAGED PENSION
                         ASSETS PARTNERSHIP 1989-C, LTD.
                    NOTES TO FINANCIAL STATEMENTS (CONTINUED)
                                   (UNAUDITED)


(6)  Fair Value of Financial Instruments -

                  The Partnership's  financial  instruments  consist of cash and
         cash equivalents and short-term  receivables and payables. The carrying
         amounts  approximate  fair value due to the highly liquid nature of the
         short-term instruments.



                                       8


<PAGE>

                          SWIFT ENERGY MANAGED PENSION
                         ASSETS PARTNERSHIP 1989-C, LTD.
                MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL
                       CONDITION AND RESULTS OF OPERATIONS


GENERAL

      The  Partnership  is formed for the purpose of investing  in  nonoperating
interests in producing oil and gas  properties  located  within the  continental
United States.  In order to accomplish  this, the  Partnership  goes through two
distinct yet  overlapping  phases with respect to its  liquidity  and results of
operations.  When the  Partnership  is formed,  it commences  its  "acquisition"
phase,  with all funds placed in short-term  investments  until required for the
acquisition of nonoperating interests.  Therefore,  the interest earned on these
pre-acquisition  investments  becomes the  primary  cash flow source for initial
partner  distributions.  As the Partnership acquires  nonoperating  interests in
producing properties,  net cash from ownership of nonoperating interests becomes
available  for  distribution,  along  with  the  investment  income.  After  all
partnership funds have been expended on nonoperating  interests in producing oil
and gas properties,  the Partnership enters its "operations"  phase. During this
phase,  income  from  nonoperating  interests  in oil  and gas  sales  generates
substantially all revenues, and distributions to partners reflect those revenues
less all  associated  partnership  expenses.  The  Partnership  may also  derive
proceeds  from  the  sale of  nonoperating  interests  in  acquired  oil and gas
properties,  when the sale of such  interests  is  economically  appropriate  or
preferable to continued operations.

LIQUIDITY AND CAPITAL RESOURCES

      The  Partnership has completed  acquisition of  nonoperating  interests in
producing oil and gas  properties,  expending  all of the limited  partners' net
commitments available for property acquisitions.

      Under the NP/OR Agreement, the Managing General Partner acquires interests
in oil and gas properties  from outside  parties and sells these interests to an
affiliated  operating  partnership,  who  in  turn  creates  and  sells  to  the
Partnership  nonoperating  interests in these same oil and gas  properties.  The
Managing  General Partner expects funds available from net profits  interests to
be distributed to the partners.

RESULTS OF OPERATIONS

      The  following  analysis  explains  changes  in the  revenue  and  expense
categories  for the quarter  ended  September  30, 1997  (current  quarter) when
compared to the quarter ended September 30, 1996  (corresponding  quarter),  and
for the nine months ended September 30, 1997 (current period),  when compared to
the nine months ended September 30, 1996 (corresponding period).

Three Months Ended September 30, 1997 and 1996

     Income  from  nonoperating  interests  decreased  15 percent in the current
quarter of 1997 when  compared to the third  quarter in 1996.  Oil and gas sales
declined  $9,282 or 12 percent in the third quarter of 1997 when compared to the
corresponding   quarter  in  1996,  primarily  due  to  decreased  gas  and  oil
production.  A decline  of 33 percent  in gas  production  and 21 percent in oil
production had a significant  impact on partnership  performance.  Also, current
quarter  gas prices  declined  10 percent or  $.25/MCF  when  compared  to third
quarter 1996 gas prices, further contributing to decreased revenues.

      Associated amortization expense decreased 50 percent or $15,281.


                                       9


<PAGE>

                          SWIFT ENERGY MANAGED PENSION
                         ASSETS PARTNERSHIP 1989-C, LTD.
                MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL
                 CONDITION AND RESULTS OF OPERATIONS (CONTINUED)


Nine Months Ended September 30, 1997 and 1996

     Income  from  nonoperating  interests  decreased  41 percent in the current
period of 1997 when compared to the  corresponding  period in 1996.  Oil and gas
sales decreased $119,560 or 34 percent in the first nine months of 1997 over the
corresponding  period in 1996. A decline of 40 percent in gas  production and 26
percent in oil  production  were  major  contributing  factors to the  decreased
revenues for the period.  Decreased gas prices of 6 percent or $.13/MCF  further
contributed to the decreased revenues.

      Associated amortization expense declined 54 percent or $56,972.

      During 1997,  partnership  revenues  and costs will be shared  between the
limited partners and general partners in a 90:10 ratio.


                                       10


<PAGE>

                          SWIFT ENERGY MANAGED PENSION
                         ASSETS PARTNERSHIP 1989-C, LTD
                           PART II - OTHER INFORMATION




ITEM 5.    OTHER INFORMATION


                                     -NONE-




                                       11


<PAGE>



                                   SIGNATURES



Pursuant to the  requirements of Section 13 or 15(d) 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.


                                      SWIFT ENERGY MANAGED PENSION
                                      ASSETS PARTNERSHIP 1989-C, LTD.
                                      (Registrant)

                           By:        SWIFT ENERGY COMPANY
                                      Managing General Partner


Date:  November 4, 1997    By:        /s/ John R. Alden
       ----------------               -----------------------------------------
                                      John R. Alden
                                      Senior Vice President, Secretary
                                      and Principal Financial Officer

Date:  November 4, 1997    By:        /s/ Alton D. Heckaman, Jr.
       ----------------               -----------------------------------------
                                      Alton D. Heckaman, Jr.
                                      Vice President, Controller
                                      and Principal Accounting Officer


                                       12