Exhibit 5.4 LETTER OF CONSENT TO: Petrofund Energy Trust We refer to the Notice of Annual and Special Meeting of Unitholders and Proxy Statement and Information Circular of Ultima Energy Trust ("Ultima") dated April 30, 2004 with respect to a business combination involving Ultima and Petrofund Energy Trust ("Petrofund") and the registration statement on Form F-10 of Petrofund dated April 30, 2004 (the "Registration Statement"). We also refer to the Annual Information Form of Petrofund dated March 15, 2004 (the "AIF"). We hereby consent to the reference to our report contained in the AIF incorporated by reference in the Registration Statement. Yours very truly, GILBERT LAUSTSEN JUNG ASSOCIATES LTD. /s/ Wayne W. Chow, P. Eng. --------------------------- Wayne W. Chow, P. Eng. Vice-President Dated: April 30, 2004 Calgary, Alberta CANADA LETTER OF CONSENT To: Petrofund Energy Trust We refer to the Notice of Annual and Special Meeting of Unitholders and Proxy Statement and Information Circular of Ultima Energy Trust ("Ultima") dated April 30, 2004 with respect to a business combination involving Ultima and Petrofund Energy Trust ("Petrofund") and the registration statement on Form F-10 of Petrofund dated April 30, 2004 (the "Registration Statement"). We also refer to the annual information form of Ultima dated April 30, 2004 (the "AIF"). We hereby consent to the reference to our report contained in the AIF incorporated by reference in the Registration Statement. Yours very truly, GILBERT LAUSTSEN JUNG ASSOCIATES LTD. /s/ Dana B. Laustsen, P. Eng. Dana B. Laustsen, P.Eng. Executive Vice-President Calgary, Alberta, Canada April 30, 2004