<PAGE>   1

                       SECURITIES AND EXCHANGE COMMISSION

                             Washington, D.C. 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 MARCH 31, 1999

                                       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 0-18169

                            IEA INCOME FUND IX, L.P.
             (Exact name of registrant as specified in its charter)

               California                                  94-3069954
      (State or other jurisdiction of                    (I.R.S. Employer
       incorporation or organization)                   Identification No.)

444 Market Street, 15th Floor, San Francisco, California       94111
    (Address of principal executive offices)                 (Zip Code)

                                 (415) 677-8990
              (Registrant's telephone number, including area code)

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>   2

                            IEA INCOME FUND IX, L.P.

                  REPORT ON FORM 10-Q FOR THE QUARTERLY PERIOD
                              ENDED MARCH 31, 1999

                                TABLE OF CONTENTS



<TABLE>
<CAPTION>
                                                                                                                     PAGE
<S>                                                                                                                 <C>
PART I - FINANCIAL INFORMATION

  Item 1.   Financial Statements


            Balance Sheets - March 31, 1999 (unaudited) and December 31, 1998                                         4


            Statements of Operations for the three months ended March 31, 1999 and 1998 (unaudited)                   5


            Statements of Cash Flows for the three months ended March 31, 1999 and 1998 (unaudited)                   6


            Notes to Financial Statements (unaudited)                                                                 7


  Item 2.   Management's Discussion and Analysis of Financial Condition and Results of Operations                    10


  Item 3.   Quantitative and Qualitative Disclosures About Market Risk                                               12


PART II - OTHER INFORMATION


  Item 1.   Legal Proceedings                                                                                        13


  Item 3.   Defaults Upon Senior Securities                                                                          13


  Item 5.   Other Information                                                                                        13


  Item 6.   Exhibits and Reports on Form 8-K                                                                         15
</TABLE>



                                       2

<PAGE>   3

                         PART I - FINANCIAL INFORMATION



Item 1.    Financial Statements

           Presented herein are the Registrant's balance sheets as of March 31,
           1999 and December 31, 1998, statements of operations for the three
           months ended March 31, 1999 and 1998, and statements of cash flows
           for the three months ended March 31, 1999 and 1998.





                                        3

<PAGE>   4


                            IEA INCOME FUND IX, L.P.

                                 BALANCE SHEETS

                                   (UNAUDITED)



<TABLE>
<CAPTION>
                                                                                   March 31,         December 31,
                                                                                    1999                1998
                                                                                ------------        ------------
<S>                                                                             <C>                 <C>         
                      Assets

Current assets:
       Cash and cash equivalents, includes $757,507 at March 31, 1999 and
             $780,329 at December 31, 1998 in interest-bearing accounts         $    757,607        $    780,429
       Net lease receivables due from Leasing Company
             (notes 1 and 2)                                                         180,457             229,107
                                                                                ------------        ------------

                      Total current assets                                           938,064           1,009,536
                                                                                ------------        ------------

Container rental equipment, at cost                                               14,009,866          14,429,687
       Less accumulated depreciation                                               7,578,762           7,605,099
                                                                                ------------        ------------
             Net container rental equipment                                        6,431,104           6,824,588
                                                                                ------------        ------------

                                                                                $  7,369,168        $  7,834,124
                                                                                ============        ============
                      Partners' Capital

Partners' capital (deficit):
       General partner                                                          $    (43,162)       $    (38,512)
       Limited partners                                                            7,412,330           7,872,636
                                                                                ------------        ------------

                      Total partners' capital                                      7,369,168           7,834,124
                                                                                ------------        ------------

                                                                                $  7,369,168        $  7,834,124
                                                                                ============        ============
</TABLE>



   The accompanying notes are an integral part of these financial statements.



                                        4

<PAGE>   5

                            IEA INCOME FUND IX, L.P.

                            STATEMENTS OF OPERATIONS

                                   (UNAUDITED)



<TABLE>
<CAPTION>
                                                           Three Months Ended
                                                       ----------------------------
                                                        March 31,         March 31,
                                                          1999              1998
                                                       ----------       -----------
<S>                                                    <C>              <C>      
Net lease revenue (notes 1 and 3)                      $ 342,744        $ 414,931
Other operating expenses:
    Depreciation                                         206,787          225,926
    Other general and administrative expenses             14,144           13,820
                                                       ---------        ---------
                                                         220,931          239,746
                                                       ---------        ---------
         Earnings from operations                        121,813          175,185

Other income (loss):
    Interest income                                        8,245           12,438
    Net loss on disposal of equipment                    (61,909)         (41,724)
                                                       ---------        ---------
                                                         (53,664)         (29,286)
                                                       ---------        ---------
         Net earnings                                  $  68,149        $ 145,899
                                                       =========        =========
Allocation of net earnings:
    General partner                                    $  18,572        $  20,244
    Limited partners                                      49,577          125,655
                                                       ---------        ---------
                                                       $  68,149        $ 145,899
                                                       =========        =========

Limited partners' per unit share of net earnings       $    1.46        $    3.70
                                                       =========        =========
</TABLE>


   The accompanying notes are an integral part of these financial statements.



                                        5

<PAGE>   6


                            IEA INCOME FUND IX, L.P.

                            STATEMENTS OF CASH FLOWS

                                   (UNAUDITED)



<TABLE>
<CAPTION>
                                                              Three Months Ended
                                                           --------------------------
                                                            March 31,        March 31,
                                                              1999             1998
                                                           ----------       ----------
<S>                                                        <C>              <C>      
Net cash provided by operating activities                  $ 345,035        $ 370,993

Cash flows provided by investing activities:
    Proceeds from sale of container rental equipment         165,247          157,711

Cash flows used in financing activities:
    Distribution to partners                                (533,104)        (641,307)
                                                           ---------        ---------

Net decrease in cash and cash equivalents                    (22,822)        (112,603)

Cash and cash equivalents at January 1                       780,429          999,900
                                                           ---------        ---------

Cash and cash equivalents at March 31                      $ 757,607        $ 887,297
                                                           =========        =========
</TABLE>



   The accompanying notes are an integral part of these financial statements.



                                        6

<PAGE>   7


                            IEA INCOME FUND IX, L.P.

                     NOTES TO UNAUDITED FINANCIAL STATEMENTS



(1)        Summary of Significant Accounting Policies

           (a)        Nature of Operations

                      IEA Income Fund IX, L.P. (the "Partnership") is a limited
                      partnership organized under the laws of the State of
                      California on June 8, 1988 for the purpose of owning and
                      leasing marine cargo containers worldwide to ocean
                      carriers. To this extent, the Partnership's operations are
                      subject to the fluctuations of world economic and
                      political conditions. Such factors may affect the pattern
                      and levels of world trade. The Partnership believes that
                      the profitability of, and risks associated with, leases to
                      foreign customers is generally the same as those of leases
                      to domestic customers. The Partnership's leases generally
                      require all payments to be made in United States currency.

                      Cronos Capital Corp. ("CCC") is the general partner and,
                      with its affiliate Cronos Containers Limited (the "Leasing
                      Company"), manages the business of the Partnership. The
                      Partnership shall continue until December 31, 2009, unless
                      sooner terminated upon the occurrence of certain events.

                      The Partnership commenced operations on December 5, 1988,
                      when the minimum subscription proceeds of $1,000,000 were
                      obtained. The Partnership offered 40,000 units of limited
                      partnership interest at $500 per unit, or $20,000,000. The
                      offering terminated on September 11, 1989, at which time
                      33,992 limited partnership units had been purchased.

           (b)        Leasing Company and Leasing Agent Agreement

                      Pursuant to the Limited Partnership Agreement of the
                      Partnership, all authority to administer the business of
                      the Partnership is vested in CCC. CCC has entered into a
                      Leasing Agent Agreement whereby the Leasing Company has
                      the responsibility to manage the leasing operations of all
                      equipment owned by the Partnership. Pursuant to the
                      Agreement, the Leasing Company is responsible for leasing,
                      managing and re-leasing the Partnership's containers to
                      ocean carriers and has full discretion over which ocean
                      carriers and suppliers of goods and services it may deal
                      with. The Leasing Agent Agreement permits the Leasing
                      Company to use the containers owned by the Partnership,
                      together with other containers owned or managed by the
                      Leasing Company and its affiliates, as part of a single
                      fleet operated without regard to ownership. Since the
                      Leasing Agent Agreement meets the definition of an
                      operating lease in Statement of Financial Accounting
                      Standards (SFAS) No. 13, it is accounted for as a lease
                      under which the Partnership is lessor and the Leasing
                      Company is lessee.

                      The Leasing Agent Agreement generally provides that the
                      Leasing Company will make payments to the Partnership
                      based upon rentals collected from ocean carriers after
                      deducting direct operating expenses and management fees to
                      CCC. The Leasing Company leases containers to ocean
                      carriers, generally under operating leases which are
                      either master leases or term leases (mostly one to five
                      years). Master leases do not specify the exact number of
                      containers to be leased or the term that each container
                      will remain on hire but allow the ocean carrier to pick up
                      and drop off containers at various locations; rentals are
                      based upon the number of containers used and the
                      applicable per-diem rate. Accordingly, rentals under
                      master leases are all variable and contingent upon the
                      number of containers used. Most containers are leased to
                      ocean carriers under master leases; leasing agreements
                      with fixed payment terms are not material to the financial
                      statements. Since there are no material minimum lease
                      rentals, no disclosure of minimum lease rentals is
                      provided in these financial statements.



                                                                    (Continued)


                                        7

<PAGE>   8

                            IEA INCOME FUND IX, L.P.

                     NOTES TO UNAUDITED FINANCIAL STATEMENTS



           (c)        Basis of Accounting

                      The Partnership utilizes the accrual method of accounting.
                      Net lease revenue is recorded by the Partnership in each
                      period based upon its leasing agent agreement with the
                      Leasing Company. Net lease revenue is generally dependent
                      upon operating lease rentals from operating lease
                      agreements between the Leasing Company and its various
                      lessees, less direct operating expenses and management
                      fees due in respect of the containers specified in each
                      operating lease agreement.

           (d)        Financial Statement Presentation

                      These financial statements have been prepared without
                      audit. Certain information and footnote disclosures
                      normally included in financial statements prepared in
                      accordance with generally accepted accounting procedures
                      have been omitted. It is suggested that these financial
                      statements be read in conjunction with the financial
                      statements and accompanying notes in the Partnership's
                      latest annual report on Form 10-K.

                      The preparation of financial statements in conformity with
                      generally accepted accounting principles (GAAP) requires
                      the Partnership to make estimates and assumptions that
                      affect the reported amounts of assets and liabilities and
                      disclosure of contingent assets and liabilities at the
                      date of the financial statements and the reported amounts
                      of revenues and expenses during the reported period.
                      Actual results could differ from those estimates.

                      The interim financial statements presented herewith
                      reflect all adjustments of a normal recurring nature which
                      are, in the opinion of management, necessary to a fair
                      statement of the financial condition and results of
                      operations for the interim periods presented.

(2)        Net Lease Receivables Due from Leasing Company

           Net lease receivables due from the Leasing Company are determined by
           deducting direct operating payables and accrued expenses, base
           management fees payable, and reimbursed administrative expenses
           payable to CCC and its affiliates from the rental billings payable by
           the Leasing Company to the Partnership under operating leases to
           ocean carriers for the containers owned by the Partnership. Net lease
           receivables at March 31, 1999 and December 31, 1998 were as follows:


<TABLE>
<CAPTION>
                                                                            March 31,     December 31,
                                                                              1999           1998
                                                                            --------      ------------
<S>                                                                         <C>            <C>     
               Lease receivables, net of doubtful accounts of $58,288
                   at March 31, 1999 and $75,951 at December 31, 1998       $480,419       $524,138
               Less:
               Direct operating payables and accrued expenses                183,622        177,061
               Damage protection reserve                                      52,043         51,003
               Base management fees                                           54,759         56,982
               Reimbursed administrative expenses                              9,538          9,985
                                                                            --------       --------
                                                                            $180,457       $229,107
                                                                            ========       ========
</TABLE>



                                                                     (Continued)

                                        8

<PAGE>   9


                            IEA INCOME FUND IX, L.P.

                     NOTES TO UNAUDITED FINANCIAL STATEMENTS



(3)        Net Lease Revenue

           Net lease revenue is determined by deducting direct operating
           expenses, base management fees and reimbursed administrative expenses
           to CCC from the rental revenue billed by the Leasing Company under
           operating leases to ocean carriers for the containers owned by the
           Partnership. Net lease revenue for the three-month periods ended
           March 31, 1999 and 1998 was as follows:


<TABLE>
<CAPTION>
                                                           Three Months Ended
                                                         ------------------------
                                                         March 31,      March 31,
                                                           1999           1998
                                                         ---------      ---------
<S>                                                      <C>            <C>     
               Rental revenue (note 4)                   $498,090       $607,334
               Less:
               Rental equipment operating expenses         94,475        110,359
               Base management fees                        36,374         42,237
               Reimbursed administrative expenses          24,497         39,807
                                                         --------       --------
                                                         $342,744       $414,931
                                                         ========       ========
</TABLE>

(4)        Operating Segment

           The Financial Accounting Standards Board has issued SFAS No. 131,
           "Disclosures about Segments of an Enterprise and Related
           Information", which changes the way public business enterprises
           report financial and descriptive information about reportable
           operating segments. An operating segment is a component of an
           enterprise that engages in business activities from which it may earn
           revenues and incur expenses, whose operating results are regularly
           reviewed by the enterprise's chief operating decision maker to make
           decisions about resources to be allocated to the segment and assess
           its performance, and about which separate financial information is
           available. Management operates the Partnership's container fleet as a
           homogenous unit and has determined, after considering the
           requirements of SFAS No. 131, that as such it has a single reportable
           operating segment.

           The Partnership derives its revenues from owning and leasing marine
           cargo containers. As of March 31, 1999, the Partnership operated
           1,959 twenty-foot, 648 forty-foot and 1,182 forty-foot high-cube
           marine dry cargo containers.

           Due to the Partnership's lack of information regarding the physical
           location of its fleet of containers when on lease in the global
           shipping trade, it is impracticable to provide the geographic area
           information required by SFAS No. 131. Any attempt to separate
           "foreign" operations from "domestic" operations would be dependent on
           definitions and assumptions that are so subjective as to render the
           information meaningless and potentially misleading.



                                        9

<PAGE>   10

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

           It is suggested that the following discussion be read in conjunction
           with the Registrant's most recent annual report on Form 10-K.

1)         Material changes in financial condition between March 31, 1999 and
           December 31, 1998.

           During the first three months of 1999, the Registrant disposed of 103
           containers as part of its ongoing container operations. At March 31,
           1999, 79% of the original equipment remained in the Registrant's
           fleet, as compared to 81% at December 31, 1998, and was comprised of
           the following:


<TABLE>
<CAPTION>
                                                                                      40-Foot
                                                        20-Foot         40-Foot      High-Cube
                                                        -------         -------      ---------
<S>                                                     <C>             <C>           <C>
               Containers on lease:
                          Term leases                      255             99            169
                          Master leases                  1,120            355            847
                                                         -----            ---          -----
                                   Subtotal              1,375            454          1,016

               Containers off lease                        584            194            166
                                                         -----            ---          -----

                          Total container fleet          1,959            648          1,182
                                                         =====            ===          =====
</TABLE>


<TABLE>
<CAPTION>
                                                                                                             40-Foot
                                                            20-Foot                  40-Foot                 High-Cube
                                                       -----------------         ----------------        ----------------- 
                                                       Units          %          Units         %         Units          %
                                                       -----         ---         -----        ---        -----         --- 
<S>                                                    <C>           <C>          <C>         <C>        <C>           <C> 
               Total purchases                         2,327         100%         799         100%       1,653         100%
                          Less disposals                 368          16%         151          19%         471          28%
                                                       -----         ---          ---         ---        -----         --- 
               Remaining fleet at March 31, 1999       1,959          84%         648          81%       1,182          72%
                                                       =====         ===          ===         ===        =====         === 
</TABLE>

           During the first quarter of 1999, distributions from operations and
           sales proceeds amounted to $533,104, reflecting distributions to the
           general and limited partners for the fourth quarter of 1998. This
           represents an increase from the $519,664 distributed during the
           fourth quarter of 1998, reflecting distributions for the third
           quarter of 1998. The increase in distributions is attributable to an
           increase in distributions from operations distributed to its
           partners.

           Growth in intra-Asian trade and improving lease-out activity in some
           key locations have expanded the requirement for leased containers in
           selected locations. As a result of these slowly improving trends,
           trade volumes in several markets are rebounding and utilization of
           the Registrant's equipment has been recently improving. However,
           per-diem rental rates remain unchanged and container imbalances are
           expected to continue for the remainder of 1999. In light of the
           encouraging signs mentioned above, the Registrant will selectively
           increase its repositioning of available equipment to higher demand
           locations when it believes that the impact will have a positive
           effect on operations.



                                       10

<PAGE>   11


2)         Material changes in the results of operations between the three-month
           period ended March 31, 1999 and the three-month period ended March
           31, 1998.

           Net lease revenue for the three-month period ended March 31, 1999 was
           $342,744, a decline of approximately 17% from the same three-month
           period in the prior year. Gross rental revenue (a component of net
           lease revenue) for the three-month period ended March 31, 1999 was
           $498,090, a decline of 18% from the same three-month period in 1998.
           Gross rental revenue was primarily impacted by a smaller fleet size
           and lower per-diem rental rates. Average per-diem rental rates for
           the three-month period ended March 31, 1999 declined 6% when compared
           to the same three-month period in the prior year. The Registrant's
           average fleet size and utilization rates for the three-month periods
           ended March 31, 1999 and 1998 were as follows:


<TABLE>
<CAPTION>
                                                                                   Three Months Ended
                                                                                --------------------------
                                                                                March 31,        March 31,
                                                                                  1999              1998
                                                                                ---------        ---------
<S>                                                                              <C>               <C>  
               Average fleet size (measured in twenty-foot equivalent
                     units (TEU))                                                5,712             6,252
               Average Utilization                                                  77%               82%
</TABLE>

           The Registrant's declining fleet size contributed to an 8% decline in
           depreciation expense when compared to the same three-month period in
           the prior year. Rental equipment operating expenses were 19% of the
           Registrant's gross lease revenue during the three-month period ended
           March 31, 1999, as compared to 18% during the three-month period
           ended March 31, 1998.

           Year 2000

           The Registrant relies upon the financial and operational systems
           provided by the Leasing Company and its affiliates, as well as the
           systems provided by other independent third parties to service the
           three primary areas of its business: investor processing/maintenance;
           container leasing/asset tracking; and accounting finance. The
           Registrant has received confirmation from its third-party investor
           processing/maintenance vendor that their system is Year 2000
           compliant. The Registrant does not expect a material increase in its
           vendor servicing fee to reimburse Year 2000 costs. Container
           leasing/asset tracking and accounting/finance services are provided
           to the Registrant by CCC and its affiliate, the Leasing Company,
           pursuant to the respective Limited Partnership Agreement and Leasing
           Agent Agreement. CCC and the Leasing Company have initiated a program
           to prepare their systems and applications for the Year 2000.
           Preliminary studies indicate that testing, conversion and upgrading
           of system applications is expected to cost CCC and the Leasing
           Company less than $500,000. Pursuant to the Limited Partnership
           Agreement, CCC or the Leasing Company, may not seek reimbursement of
           data processing costs associated with the Year 2000 program. The
           financial impact of making these required system changes is not
           expected to be material to the Registrant's financial position,
           results of operations or cash flows.



                                       11

<PAGE>   12

           Cautionary Statement

           This Quarterly Report on Form 10-Q contains statements relating to
           future results of the Registrant, including certain projections and
           business trends, that are "forward-looking statements" as defined in
           the Private Securities Litigation Reform Act of 1995. Actual results
           may differ materially from those projected as a result of certain
           risks and uncertainties, including but not limited to changes in:
           economic conditions; trade policies; demand for and market acceptance
           of leased marine cargo containers; competitive utilization and
           per-diem rental rate pressures; as well as other risks and
           uncertainties, including but not limited to those described above in
           the discussion of the marine container leasing business under Item
           2., Management's Discussion and Analysis of Financial Condition and
           Results of Operations; and those detailed from time to time in the
           filings of the Registrant with the Securities and Exchange
           Commission.

Item 3.    Quantitative and Qualitative Disclosures About Market Risk

           Not applicable.




                                       12

<PAGE>   13


                           PART II - OTHER INFORMATION


Item 1.    Legal Proceedings

           As reported in the Registrant's Current Report on Form 8-K and
           Amendment No. 1 to Current Report on Form 8-K, filed with the
           Commission on February 7, 1997 and February 26, 1997, respectively,
           Arthur Andersen, London, England, resigned as auditors of The Cronos
           Group, (the "Parent Company"), on February 3, 1997.

           The Parent Company is the indirect corporate parent of CCC, the
           general partner of the Registrant. In its letter of resignation to
           the Parent Company, Arthur Andersen stated that it resigned as
           auditors of the Parent Company and all other entities affiliated with
           the Parent Company. While its letter of resignation was not addressed
           to CCC, Arthur Andersen confirmed to CCC that its resignation as
           auditors of the entities referred to in its letter of resignation
           included its resignation as auditors of CCC and the Registrant.

           CCC does not believe, based upon the information currently available
           to it, that Arthur Andersen's resignation was triggered by any
           concern over the accounting policies and procedures followed by the
           Registrant.

           Arthur Andersen's reports on the financial statements of CCC and the
           Registrant, for years preceding 1996, had not contained an adverse
           opinion or a disclaimer of opinion, nor were any such reports
           qualified or modified as to uncertainty, audit scope, or accounting
           principles.

           During the Registrant's fiscal year ended December 31, 1995 and the
           subsequent interim period preceding Arthur Andersen's resignation,
           there were no disagreements between CCC or the Registrant and Arthur
           Andersen on any matter of accounting principles or practices,
           financial statement disclosure, or auditing scope or procedure.

           In connection with its resignation, Arthur Andersen also prepared a
           report pursuant to the provisions of Section 10A(b)(2) of the
           Securities Exchange Act of 1934, as amended, for filing by the Parent
           Company with the Securities and Exchange Commission (the "SEC").
           Following the report of Arthur Andersen, the SEC, on February 10,
           1997, commenced a private investigation of the Parent Company for the
           purpose of investigating the matters discussed in such report and
           related matters. The Registrant does not believe that the focus of
           the SEC's investigation is upon the Registrant or CCC. CCC is unable
           to predict the outcome of the SEC's ongoing private investigation of
           the Parent Company.

Item 3.    Defaults Upon Senior Securities

           See Item 5. Other Information.

Item 5.    Other Information

           In 1993, the Parent Company negotiated a credit facility
           (hereinafter, the "Credit Facility") with several banks for the use
           by the Parent Company and its subsidiaries, including CCC. At
           December 31, 1996, approximately $73,500,000 in principal
           indebtedness was outstanding under the Credit Facility. As a party to
           the Credit Facility, CCC is jointly and severally liable for the
           repayment of all principal and interest owed under the Credit
           Facility. The obligations of CCC, and the five other subsidiaries of
           the Parent Company that are borrowers under the Credit Facility, are
           guaranteed by the Parent Company.




                                       13

<PAGE>   14

           Following negotiations in 1997 with the banks providing the Credit
           Facility, an Amended and Restated Credit Agreement was executed in
           June 1997, subject to various actions being taken by the Parent
           Company and its subsidiaries, primarily relating to the provision of
           additional collateral. This Agreement was further amended in July
           1997 and the provisions of the Agreement and its Amendment converted
           the facility to a term loan, payable in installments, with a final
           maturity date of May 31, 1998. The terms of the Agreement and its
           Amendment also provided for additional security over shares in the
           subsidiary of the Parent Company that owns the head office of the
           Parent Company's container leasing operations. They also provided for
           the loans to the former Chairman of $5,900,000 and $3,700,000 to be
           restructured as obligations of the former Chairman to another
           subsidiary of the Parent Company (not CCC), together with the pledge
           to this subsidiary company of 2,030,303 Common Shares beneficially
           owned by him in the Parent Company as security for these loans. They
           further provided for the assignment of these loans to the lending
           banks, together with the pledge of 1,000,000 shares and the
           assignment of the rights of the Parent Company in respect of the
           other 1,030,303 shares. Additionally, CCC granted the lending banks a
           security interest in the fees to which it is entitled for the
           services it renders to the container leasing partnerships of which it
           acts as general partner, including its fee income payable by the
           Registrant. The Parent Company did not repay the Credit Facility at
           the amended maturity date of May 31, 1998.

           On June 30, 1998, the Parent Company entered into a third amendment
           (the "Third Amendment") to the Credit Facility. Under the Third
           Amendment, the remaining principal amount of $36,800,000 was to be
           amortized in varying monthly amounts commencing on July 31, 1998 with
           $26,950,000 due on September 30, 1998 and a final maturity date of
           January 8, 1999. The Parent Company did not repay the amounts due on
           September 30, 1998 and January 8, 1999. The balance outstanding on
           the Credit Facility at December 31, 1998 was $33,110,000.

           In March 1999, the Parent Company agreed to a fourth amendment (the
           "Fourth Amendment") to the Bank Facility under which the final
           maturity date will be September 1999. The Fourth Amendment became
           effective as of March 31, 1999 subject to the satisfaction thereafter
           of various conditions, including the delivery of the Parent Company's
           audited financial statements for 1998, together with various legal
           opinions and other loan documentation by April 15, 1999. This date
           was extended to April 30, 1999. The Parent Company furnished the
           required legal opinions and other loan documentation which are now
           under review.

           The directors of the Parent Company also are pursuing alternative
           sources of financing to meet the amended repayment obligations
           anticipated under the Fourth Amendment. Failure to meet revised
           lending terms would constitute an event of default with the lenders.
           The declaration of an event of default would result in further
           defaults with other lenders under loan agreement cross-default
           provisions. Should a default of the term loans be enforced, the
           Parent Company and CCC may be unable to continue as going concerns.

           The Registrant is not a borrower under the Credit Facility, and
           neither the containers nor the other assets of the Registrant have
           been pledged as collateral under the Credit Facility.

           CCC is unable to determine the impact, if any, these issues may have
           on the future operating results, financial condition and cash flows
           of the Registrant or CCC and on the Leasing Company's ability to
           manage the Registrant's fleet in subsequent periods.



                                       14

<PAGE>   15


Item 6.    Exhibits and Reports on Form 8-K

(a)        Exhibits


<TABLE>
<CAPTION>
            Exhibit
               No.                          Description                                        Method of Filing
            -------       ----------------------------------------------------             ------------------------
<S>                      <C>                                                              <C>
              3(a)        Limited Partnership Agreement of the Registrant,
                          amended and restated as of September 12, 1988                    *

              3(b)        Certificate of Limited Partnership of the Registrant             **

              27          Financial Data Schedule                                          Filed with this document
</TABLE>


(b)        Reports on Form 8-K

           No reports on Form 8-K were filed by the Registrant during the
quarter ended March 31, 1999.





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


*          Incorporated by reference to Exhibit "A" to the Prospectus of the
           Registrant dated September 12, 1988, included as part of Registration
           Statement on Form S-1 (No. 33-23321)

**         Incorporated by reference to Exhibit 3.4 to the Registration
           Statement on Form S-1 (No. 33-23321)



                                       15

<PAGE>   16

                                   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.



                                       IEA INCOME FUND IX, L.P.


                                       By  Cronos Capital Corp.
                                           The General Partner


                                       By  /s/ Dennis J. Tietz
                                           ----------------------------------
                                           Dennis J. Tietz
                                           President and Director of Cronos 
                                           Capital Corp. ("CCC")
                                           Principal Executive Officer of CCC





Date: May 15, 1999



                                       16

<PAGE>   17

                                  EXHIBIT INDEX


<TABLE>
<CAPTION>
            Exhibit
               No.                          Description                                        Method of Filing
            -------       ----------------------------------------------------             ------------------------
<S>                      <C>                                                              <C>
              3(a)        Limited Partnership Agreement of the Registrant,
                          amended and restated as of September 12, 1988                    *

              3(b)        Certificate of Limited Partnership of the Registrant             **

              27          Financial Data Schedule                                          Filed with this document
</TABLE>





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

*          Incorporated by reference to Exhibit "A" to the Prospectus of the
           Registrant dated September 12, 1988, included as part of Registration
           Statement on Form S-1 (No. 33-23321)

**         Incorporated by reference to Exhibit 3.4 to the Registration
           Statement on Form S-1 (No. 33-23321)