<PAGE>   1

                                                                     Page 1 of 8

                                    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:  March 31, 2000

OR

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

For the transition period from ____________ to ______________

Commission file number:  33-51630
                         --------

                      CHIEFTAIN INTERNATIONAL FUNDING CORP.
                      -------------------------------------
             (Exact name of registrant as specified in its charter)

             Nevada                                    98-0127391
------------------------------------     ---------------------------------------
  (State or other jurisdiction of         (I.R.S. Employer Identification No.)
   incorporation or organization)

1201 TD Tower, 10088 - 102 Avenue
Edmonton, Alberta, Canada                                      T5J  2Z1
--------------------------------------------            ------------------------
(Address of principal executive offices)                 (Zip Code/Postal Code)

Registrants' telephone number, including area code:  (780) 425-1950

                                 Not Applicable
           ------------------------------------------------------------
             (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
    -------       ------

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

<TABLE>
<CAPTION>

Title of each Class                     Date                Number Outstanding
---------------------------       -------------------     ---------------------
<S>                               <C>                         <C>
Common Shares, no par value         April 17, 2000              200,000
</TABLE>



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                                                                     Page 2 of 8



                      CHIEFTAIN INTERNATIONAL FUNDING CORP.

                                      INDEX


                                                                        Page No.

PART I:  FINANCIAL STATEMENTS


     Item 1.           Financial Statements

     Chieftain International Funding Corp.

     Consolidated Condensed Balance Sheet -
              March 31, 2000 and December 31, 1999                             3

     Consolidated Condensed Statement of Income and Retained Earnings -
              Three months ended March 31, 2000 and 1999                       4

     Consolidated Condensed Statement of Cash Flows
              Three months ended March 31, 2000 and 1999                       5

     Notes to Consolidated Condensed Financial Statements                      6

     Item 2.           Management's Discussion and Analysis of
                       Financial Condition and Results of Operations           7


     Signatures                                                                8



















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                                                                     Page 3 of 8

CHIEFTAIN INTERNATIONAL FUNDING CORP.

(a subsidiary of Chieftain International (U.S.) Inc.)

BALANCE SHEET

<TABLE>
<CAPTION>
                                                                   MARCH 31         December 31
                                                                     2000              1999
---------------------------------------------------------------------------------------------------------------------
(US$)
(unaudited)
ASSETS

<S>                                                              <C>                <C>
Current assets:
     Cash                                                        $    86,858        $   147,982
     Due from affiliated companies                                 5,675,001          5,392,730
                                                               ----------------------------------
                                                                   5,761,859          5,540,712

Investment in preferred shares of Chieftain International
     (U.S.) Inc. at cost                                          78,500,000         78,500,000
                                                               ----------------------------------

                                                                 $84,261,859        $84,040,712
                                                               ==================================

LIABILITIES AND SHAREHOLDERS' EQUITY

Current liabilities:
     Accounts payable and accrued                                $     5,305        $     5,305

Preferred shares issued (Note 2)                                  63,402,903         63,402,903

Common shareholder's equity:
     Share capital
       Authorized
        10,000,000 common shares, par value $0.01 each
       Issued                                                          2,000              2,000
        200,000 common shares
     Additional paid in capital                                   14,998,000         14,998,000
     Retained earnings                                             5,853,651          5,632,504
                                                               ----------------------------------
                                                                  20,853,651         20,632,504
                                                               ----------------------------------

                                                                 $84,261,859        $84,040,712
                                                               ==================================
</TABLE>




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CHIEFTAIN INTERNATIONAL FUNDING CORP.

STATEMENT OF INCOME AND RETAINED EARNINGS


<TABLE>
<CAPTION>
                                                             Three months ended
                                                                   March 31
                                                           2000               1999
----------------------------------------------------------------------------------------
 (US$)
 (unaudited)

<S>                                                    <C>                 <C>
Revenue:
     Dividends                                         $ 1,422,813         $ 1,422,813
     Interest                                               70,892              46,976
                                                     ----------------------------------

                                                         1,493,705           1,469,789
Expense:
     General and administrative                             18,022               8,293
                                                     ----------------------------------

Income before income taxes and
dividends on preferred shares                            1,475,683           1,461,496
Income tax expense  - (Note 3)                              19,000              14,000
                                                     ----------------------------------

Net income before dividends on preferred shares          1,456,683           1,447,496

Dividends on preferred shares                           (1,235,536)         (1,235,536)
                                                     ----------------------------------


Net income applicable to common shares                     221,147             211,960

Retained earnings, beginning of period                   5,632,504           4,784,505
                                                     ----------------------------------

Retained earnings, end of period                       $ 5,853,651         $ 4,996,465
                                                     ==================================

</TABLE>



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                                                                     Page 5 of 8

CHIEFTAIN INTERNATIONAL FUNDING CORP.

STATEMENT OF CASH FLOWS

<TABLE>
<CAPTION>
Three months ended March 31                           2000             1999
-------------------------------------------------------------------------------
(US$)
(unaudited)

<S>                                                <C>               <C>
Operating activities:
     Net income applicable to common shares        $ 221,147         $ 211,960
     Change in non-cash working capital -
         Current liabilities                            --              (2,778)
                                                 ------------------------------

                                                     221,147           209,182

Investing activity:
     Advances to affiliated companies               (282,271)         (287,557)
                                                 ------------------------------

Change in cash                                       (61,124)          (78,375)

Beginning cash                                       147,982           121,495
                                                 ------------------------------

Ending cash                                        $  86,858         $  43,120
                                                 =============================
</TABLE>


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CHIEFTAIN INTERNATIONAL FUNDING CORP.

NOTES TO FINANCIAL STATEMENTS

March 31, 2000 and 1999

(unaudited)

1.   Basis of Presentation:

     In the opinion of Chieftain International Funding Corp. ("Funding Corp."),
     the accompanying unaudited financial statements contain all adjustments
     (consisting of only normal recurring adjustments) necessary to present
     fairly the financial position as at March 31, 2000 and December 31, 1999
     and the results of operations and cash flows for the three months ended
     March 31, 2000 and 1999. Certain information and notes normally included in
     Funding Corp.'s financial statements prepared in accordance with Canadian
     generally accepted accounting principles have been condensed or omitted for
     interim reporting pursuant to the rules and regulations of the Securities
     and Exchange Commission. These financial statements should be read in
     conjunction with the financial statements and the notes thereto included in
     Funding Corp.'s Annual Report on Form 10-K for the year ended December 31,
     1999.

     Preparation of financial statements in conformity with generally accepted
     accounting principles requires management to make informed judgements and
     estimates. Actual results may differ from those estimates.

     The results of operations and cash flows for the three month period ended
     March 31, 2000 are not necessarily indicative of the results to be expected
     for the full year.

2.   Preferred Shares:

     The Articles of Funding Corp. authorize the issuance of a maximum of
     10,000,000 preferred shares with a par value of $1.00 each.

     In 1992, Funding Corp. sold 2,726,700 shares of $1.8125 convertible
     redeemable preferred stock at $25.00 per share through an underwritten
     public offering in the United States. Proceeds of the issuance of preferred
     shares, net of offering costs of $4.7 million, were $63.4 million.

3.   Income Taxes:

     Funding Corp. and its parent company file corporate income tax returns on a
     consolidated basis. As a result, income taxes payable have been offset by
     the parent company's tax losses and are reflected in the amount due from
     the parent company.





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                                                                     Page 7 of 8

         MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND
                              RESULTS OF OPERATIONS


Chieftain International Funding Corp., a special purpose subsidiary of
Chieftain International (U.S.) Inc., was formed in 1992 for the primary
purpose of financing the U.S. business operations of its parent.

Analysis of Operating Results - Three months ended March 31, 2000 and 1999

Funding Corp.'s income is derived from dividends on preferred shares and
interest on short-term notes, all of which are issued by its parent company,
Chieftain International (U.S.) Inc.

Dividends received on 3,140,000 redeemable Class B preferred shares amounted to
$1,422,813 for each of the first three months of 2000 and 1999.

Interest earned on short-term notes for the first three months of 2000 was
$70,892, a 51% increase from the amount earned in the comparable 1999 period.
Such increase resulted from a 21% increase in average investment yield and a 24%
increase in the average amount invested compared to the 1999 first three months.
Future dividend income is expected to remain constant while interest income
should increase, subject to rate fluctuations, reflecting increases in
short-term investment amounts.

Income taxes are calculated on interest income less general and administrative
costs. Dividends received from the parent are tax exempt.

Capital Resources and Liquidity

Funding Corp. is dependent upon the dividend income from its investment in
preferred shares of its parent company to provide funds for payment of dividends
on its publicly-held preferred shares.

Funds provided from operations increased to $221,147 for the first three months
of 2000 compared with $209,182 for the 1999 comparable period. Funds not
required for current working capital were invested in short-term notes issued
and payable by the parent company.

Cash balances at March 31, 2000 and 1999 were $86,858 and $43,120, respectively.

Information Regarding Forward Looking Financial Statements

This 10-Q contains forward-looking statements that are subject to risk factors
associated with the Company's business. The Company believes that the
expectations reflected in these statements are reasonable, but may be affected
by a variety of factors affecting the Company's business.



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                                                                     Page 8 of 8
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.

Chieftain International Funding Corp.
-------------------------------------
           (Registrant)





/s/ STANLEY A. MILNER
----------------------------------------------------
Stanley A. Milner, A.O.E., LL.D.
President and Chief Executive Officer
Principal Executive and Financial Officer

Dated:  April 17, 2000