<PAGE>   1





                       SECURITIES AND EXCHANGE COMMISSION
                              WASHINGTON, DC 20549
                                    Form 10-Q



 X      QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES
----    EXCHANGE ACT OF 1934 FOR THE QUARTERLY PERIOD ENDED JUNE 30, 1998.

        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:  0-16601 (formerly 33-16164-LA)
                         ------------------------------


                       FMG RITA RANCH LIMITED PARTNERSHIP
                       ----------------------------------
                           (Exact name of registrant)


Delaware                                                    23-2466343
--------                                                    ----------
(State or other jurisdiction of                      (I.R.S. Employer
incorporation or organization)                               Identification No.)

250 King of Prussia Road, Radnor, PA  19087
-------------------------------------------
(Address of Principal Executive Offices)

Issuer's Telephone Number:  (610 964-7234)
                            --------------

Indicate by check mark whether the registrant (a) 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>   2


PART I - FINANCIAL INFORMATION

Item 1 - Financial Statements

         The unaudited financial statements of FMG Rita Ranch Limited
partnership (the "Partnership") at June 30, 1998 are attached hereto as Exhibit
A.

         In the opinion of management, the accompanying unaudited condensed
financial statements include all adjustments, which are of a normal recurring
nature, necessary to present fairly the Partnership's financial position as of
June 30, 1998, and the results of its operations and cash flows for the three
months ended June 30, 1998.

Item 2 - Management's Discussion and Analysis of Financial Condition and Results
of Operations.

         Background

         The Partnership is a Delaware limited partnership. The Partnership was
formed on January 30, 1987 by FMG Western Region Acquisitions, Inc. (the
"General Partner") and the initial limited partner, FM Initial, Inc., with an
initial contribution of $25,000 by the General Partner. The General Partner is
an indirect wholly-owned subsidiary of The Fidelity Mutual Life Insurance
Company (in Rehabilitation) ("Fidelity Mutual"). In accordance with the Amended
and Restated Limited partnership Agreement dated December 17, 1987 (the
"Partnership Agreement"), FM Initial, Inc. withdrew from the partnership upon
admittance of new limited partners. The Partnership was formed to acquire and
realize appreciation in a certain 118 acre parcel of undeveloped land near
Tucson, Arizona (the "Property") by holding it for investment and eventual sale,
although there is no assurance that this will be attained.

         Results of Operations

         The Partnership had no revenues for the second quarter of 1998.
Expenses for the second quarter of 1998 consisted of general and administrative
costs of $2,067, management fees of $3,750, insurance of $29 and real estate
taxes of $2,238.

         The Partnership's revenues for the second quarter of 1997 consisted of
interest income of $1 and partnership transfer fees of $75. Expenses for the
second quarter of 1997 consisted of general and administrative costs of $1,655,
management fees of $3,750, insurance of $27 and real estate taxes of $2,366.

         The Partnership's revenues for the second quarter of 1996 consisted of
interest income of $2 and partnership transfer fees of $25. Expenses for the
second quarter of 1996 consisted of


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general and administrative costs of $1,875, management fees of $3,750, insurance
of $34 and real estate taxes of $2,604.

         The Partnership had no revenues for the first quarter of 1998. Expenses
for the first quarter of 1998 consisted of general and administrative costs of
$3,367, management fees of $3,750, insurance of $30 and real estate taxes of
$2,239.

         The Partnership's revenues for the first quarter of 1997 consisted of
interest income of $2. Expenses for the first quarter of 1997 consisted of
general and administrative costs of $1,255, management fees of $3,750, insurance
of $27 and real estate taxes of $2,367.

         The Partnership's revenues for the first quarter of 1996 consisted of
interest income of $2 and partnership transfer fees of $75. Expenses for the
first quarter of 1996 consisted of general and administrative costs of $1,430,
management fees of $3,750, insurance of $35 and real estate taxes of $2,604.

         The General Partner has no plans to develop the Property, except for
activities including land planning, market surveys and other activities
necessary to prepare the Property for sale. There can be no assurance that
necessary funds would be available should it be desirable for the Partnership to
improve the Property to facilitate its sale.

         Because of the lack of demand for industrial and commercial land in the
Tucson area and the resulting decline in the Property's value, the Partnership
was required to reduce its carrying value on the Property in 1990 and again in
1992. Class "A" Business Park lots dominate the industrial land sales market.
Sale prices range from $1.00 to $2.15 per square foot for 5 to 20 acre parcels.
There have not been any bulk sale transactions since the RTC was disposing of
it's properties. The General Partner believes that it would be necessary for the
Partnership to hold the property for several years, possibly decades, before the
Partnership may be able to sell the Property at a price which approximates the
price paid by the Partnership for the Property. Thus, it is unlikely that the
Property will be sold for a price which approximates the original price paid by
the Partnership for the Property. The Partnership anticipates a sale price of
$4,000 to $5,000 per acre.

         During 1990 and 1992, the Partnership recorded writedowns of $6,261,041
and $830,000 respectively.

         Liquidity and Capital Resources

         The Partnership has no cash reserve remaining at June 30, 1998. As
shown in the accompanying financial statements, the Partnership has incurred
substantial operating losses in each of the past three years. Such losses will
continue until the Partnership begins to sell land parcels. In the partnership
agreement, the General Partner has committed to contribute up to


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$600,000 to the capital of the Partnership as the need for additional working
capital arises. Cumulative amounts funded by the General Partner amounted to
$314,923 at June 30, 1998. Realization of the partnership's assets is dependent
upon the continued funding of operating deficits by the General Partner and its
affiliate. There can be no assurance, however, that the General Partner or its
affiliate will continue to fund operating deficits.

         The property is listed for sale with Grubb & Ellis of Tucson, Arizona.
The listing is from March 1, 1998 to November 30, 1998. A sale price of $4,000
to $5,000 an acre is anticipated.

         Impact of Year 2000

         The Partnership's management has assessed the Year 2000 technology
issue, and has developed an action plan to address the issue. Management
believes that its action plan will be implemented and completed in a timely
fashion, and that it will not materially affect the Partnership's future
operating results or future financial condition.

PART II - OTHER INFORMATION

Item 1 - Legal Proceedings

         The Partnership is not a direct party to, nor is the Partnership's
property directly the subject of, any material legal proceedings. However, on
November 6, 1992, the Commonwealth Court of Pennsylvania issued an order placing
The Fidelity Mutual Life Insurance Company ("Fidelity Mutual"), the indirect
parent of the General Partner of the Partnership, into rehabilitation under the
control and authority of the Pennsylvania Insurance Commissioner pursuant to the
provisions of the Pennsylvania Insurance Department Act, 40 P.S. Section 221.1
et seq. The Partnership is not a direct party to the order, but ownership of
the stock of the General Partner and the stock of the majority Limited Partner
is vested in the Insurance Commissioner pursuant to the Order.

Item 2 - Changes in Securities

         There was no change in the partnership's securities during the second
quarter of 1998.


Item 3 - Defaults Upon Senior Securities

         There was no default in the payment of principal, interest, a sinking
or purchase fund installment or any other default with respect to any
indebtedness of the Partnership. The Partnership has issued no preferred stock;
accordingly, there has been no arrearages or delinquencies with respect to any
such preferred stock.


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Item 4 - Submission of Matters to a Vote of Security Holders

         No matters were submitted to the Partners for a vote during the
second quarter of 1998.


Item 5 - Other Information

         None


Item 6 - Exhibits and Reports on Form 8-K

Reports on Form 8-K

         None

Exhibits (numbered in accordance with Item 601 of Regulation S-K)

<TABLE>
<CAPTION>
Exhibit Numbers                Description                          Page Number
---------------                -----------                          -----------
<S>                            <C>                                  <C>
3.1(a)                         Certificate of Limited               *
                               Partnership

3.1(b) & (4)                   Restated Limited Partnership         **
                               Agreement

9                              not applicable

11                             not applicable

12                             not applicable

13                             not applicable

16                             not applicable

18                             not applicable

19                             not applicable

22                             not applicable
</TABLE>


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<PAGE>   6

<TABLE>
<S>                            <C>
23                             not applicable

24                             not applicable

25                             not applicable

28                             not applicable

29                             not applicable
</TABLE>

*Incorporated by reference to Exhibit 3.1 filed as part of the Exhibits to the
Partnership's Registration Statement on Form S-18, Registration No. 33-16164-LA.

**   Incorporated by reference to Exhibit 3.2 filed as part of the partnership's
Registration Statement on Form S-18, Registration No. 33-16164-LA.



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                                    SIGNATURE


           Pursuant to the requirements of the Securities Exchange Act of 1934,
this Report has been signed below by the following persons on behalf of the
Registrant and in the capacities and on the date indicated.

<TABLE>
<CAPTION>
Signature                         Title                             Date
---------                         -----                             ----
<S>                               <C>                             <C>
/s/ ARTHUR W. MULLIN              President,                        8/5   1998
--------------------              Treasurer,                      --------
Arthur W. Mullin                  Director of
                                  FMG Western
                                  Region
                                  Acquisitions,
                                  Inc.






/s/ JAMES W. KELICAN, JR.         Vice President,                   8/5   1998
-------------------------         Director of                     --------
James W. Kelican, Jr.             FMG Western
                                  Region
                                  Acquisitions,
                                  Inc.
</TABLE>


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<PAGE>   8



EXHIBIT A

                       FMG RITA RANCH LIMITED PARTNERSHIP

                                 BALANCE SHEETS


<TABLE>
<CAPTION>
                                                            June 30,             December 31,
                                                              1998                  1997
                                                          (Unaudited)
                                                         --------------          --------------
<S>                                                     <C>                     <C>
ASSETS
------


Land held for sale, net                                 $      350,000          $     350,000

Cash and cash equivalents                                          519                    519

Prepaid Insurance                                                   30                      -
                                                         --------------          --------------

                                                        $      350,549          $     350,519
                                                         ==============          ==============



LIABILITIES AND PARTNERS' EQUITY
--------------------------------


   Accrued expenses                                     $       10,852          $       9,906

   Due to affiliates                                                 -                  3,750

   Partners' Equity                                            339,697                336,863
                                                         --------------          --------------

                                                        $      350,549          $     350,519
                                                         ==============          ==============
</TABLE>







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<PAGE>   9








                  F M G RITA RANCH LIMITED PARTNERSHIP

             STATEMENTS OF OPERATIONS AND PARTNERS' EQUITY


<TABLE>
<CAPTION>
                                                (Unaudited)

                                     Three months        Three months         Six months         Six months
                                         ended              ended               ended               ended
                                       June 30,            June 30,            June 30,           June 30,
                                         1998                1997                1998               1997
                                    ---------------    ----------------    ----------------    ---------------
<S>                                <C>                <C>                 <C>                 <C>
REVENUES:
  Interest income                  $             0    $              1    $              0    $             3
  Other income                                   0                  75                   0                 75
                                    ---------------    ----------------    ----------------    ---------------

                                                 0                  76                   0                 78
                                    ---------------    ----------------    ----------------    ---------------


EXPENSES:
  Real estate taxes                          2,238               2,366               4,477              4,733
  Management fees                            3,750               3,750               7,500              7,500
  General and administrative                 2,067               1,655               5,434              2,910
  Insurance                                     29                  27                  59                 54
                                    ---------------    ----------------    ----------------    ---------------


                                             8,084               7,798              17,470             15,197
                                    ---------------    ----------------    ----------------    ---------------


          NET LOSS                 $        (8,084)   $         (7,722)   $        (17,470)   $       (15,119)

Partners' equity,
   Beginning of period                     338,460             338,217             336,863            336,856

Captial Contributions                        9,321               8,893              20,304             17,651
                                    ---------------    ----------------    ----------------    ---------------


Partners' equity,
   End of period                   $       339,697    $        339,388    $        339,697    $       339,388
                                    ===============    ================    ================    ===============


Weighted Average Number of
   Limited Partnership Units
   Outstanding                               6,707               6,707               6,707              6,707
                                    ===============    ================    ================    ===============


Loss from Operations per
   Limited Partnership
   Interest                        $         (1.19)   $          (1.14)   $          (2.57)   $         (2.23)
                                    ===============    ================    ================    ===============

</TABLE>


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<PAGE>   10








                     F M G RITA RANCH LIMITED PARTNERSHIP

                     STATEMENTS OF OPERATIONS AND PARTNERS'


                               (Unaudited)

<TABLE>
<CAPTION>

                                                          SIX MONTHS
                                                         ENDED JUNE 30
                                     ------------------------------------------------------

                                          1998                 1997               1996
                                     ---------------     ----------------    --------------
<S>                                 <C>                 <C>                 <C>
REVENUES:
  Interest income                   $             0     $              3    $            4
  Other income                                    0                   75               100
                                     ---------------     ----------------    --------------


                                                  0                   78               104
                                     ---------------     ----------------    --------------

EXPENSES:
  Real estate taxes                           4,477                4,733             5,208
  Management fees                             7,500                7,500             7,500
  General and administrative                  5,434                2,910             3,305
  Insurance                                      59                   54                69
                                     ---------------     ----------------    --------------

                                             17,470               15,197            16,082
                                     ---------------     ----------------    --------------


          NET LOSS                  $       (17,470)    $        (15,119)   $      (15,978)

Partners' equity,
   Beginning of period                      336,863              336,856           336,613

Capital Contributions                        20,304               17,651            18,390
                                     ---------------     ----------------    --------------

Partners' equity,
   End of period                    $       339,697     $        339,388    $      339,025
                                     ===============     ================    ==============


Weighted Average Number of
   Limited Partnership Units
   Outstanding                                6,707                6,707             6,707
                                     ===============     ================    ==============


Loss from Operations per
   Limited Partnership Interest     $         (2.57)    $          (2.23)   $        (2.36)
                                     ===============     ================    ==============

</TABLE>

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<PAGE>   11








                      F M G RITA RANCH LIMITED PARTNERSHIP

                            STATEMENTS OF CASH FLOWS

                                  (Unaudited)

<TABLE>
<CAPTION>

                                                                  FOR THE SIX MONTHS
                                                                    ENDED JUNE 30
                                                  -----------------------------------------------


                                                       1998             1997            1996
                                                  --------------    -------------   -------------
<S>                                              <C>               <C>             <C>
CASH FLOWS FROM OPERATING ACTIVITIES:

    Net income (loss)                            $      (17,470)   $    (15,119)   $    (15,978)
    Adjustments to reconcile net
       income (loss) to net cash
       used in operating activities:

       Increase in General Partner's
          capital                                        20,304          17,651          18,390
      (Increase) in prepaid expenses                        (30)            (27)            (35)
      Increase (decrease) in
          accrued expenses                                  946           1,272           1,416
      Increase (decrease) in
          due to affiliate                               (3,750)         (3,750)         (3,750)
                                                  ---------------   -------------   -------------


       Net cash provided by (used in)
          operating activities                   $            0    $         27    $         43
                                                  ---------------   -------------   -------------


       Cash, Beginning of period                            519             267             205


       Cash, End of period                       $          519    $        294    $        248
                                                  ===============   =============   =============
</TABLE>







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