LETTER AGREEMENT, DATED FEBRUARY 12, 2004

EXHIBIT 10.21

LETTER AGREEMENT

This LETTER AGREEMENT (this “Agreement”) is entered into as of February 12, 2004, between Trump Taj Mahal Associates, a New Jersey general partnership (“Trump Taj Mahal”) and DLJ Merchant Banking Partners III, L.P., a Delaware limited partnership (“DLJMB”).

WHEREAS, on January 21, 2004, Trump Hotels & Casino Resorts, Inc., a Delaware corporation (the “Company”) and DLJMB entered into an Exclusivity Agreement (the “Exclusivity Agreement”) setting forth certain matters related to a possible transaction pursuant to which DLJMB would make a substantial equity investment in the Company in connection with a restructuring of the debt securities of the Company’s subsidiaries and its controlled affiliates (the “Transaction”), which agreement remains in full force and effect;

WHEREAS, the Company has advised DLJMB that it has determined that it will publicly disclose the fact that it has entered into the Exclusivity Agreement with DLJMB and is in active negotiations with respect to the Transaction, as described in the term sheet being discussed by the Company and DLJMB;

WHEREAS, the Exclusivity Agreement provides that DLJMB may terminate such discussions with the Company with respect to the Transaction if such a disclosure is made without its consent;

WHEREAS, DLJMB is concerned about the risks attendant to negotiating the Transaction in a public forum, the reputational issues associated with the possible failure to consummate the Transaction, and the uncertainties associated with accomplishing the restructuring of the Company’s subsidiaries’ and its controlled affiliates’ debt as well as the significant time, effort and expense which needs to be devoted to the project;

WHEREAS, DLJMB nonetheless remains interested in the Transaction;

WHEREAS, Trump Taj Mahal has a substantial interest in the Transaction being consummated and has determined that entering into this Agreement is necessary in order to assure DLJMB’s continued pursuit of the Transaction;

WHEREAS, in light of the potential “stalking horse” role which may be played by DLJMB and Trump Taj Mahal’s desire to consummate the Transaction, Trump Taj Mahal has determined to provide some certainty to DLJMB in connection with the significant time, effort and expense which DLJMB will continue to expend in order to consummate the Transaction; and

WHEREAS, the Board of Directors of Trump Taj Mahal has determined that it is in the best interests of Trump Taj Mahal and its various constituencies for Trump Taj Mahal to enter into this Agreement.

NOW, THEREFORE, in consideration of the foregoing and other good and valuable consideration, and intending to be legally bound, the parties hereto agree as follows:

1. Expenses. Trump Taj Mahal shall reimburse DLJMB for all Transaction Expenses (as defined in the Exclusivity Agreement) incurred by DLJMB beginning after the date of this Agreement and accruing until, and shall be payable upon, the earlier to occur of (i) the consummation of an Alternative Transaction (as defined below) and (ii) the date that is eighteen months following the date of this Agreement; provided, however, Transaction Expenses through such date shall be payable immediately upon the sale (whether through a stock sale or sale of assets) of either the Trump Marina Hotel Casino or the Trump Indiana Casino Hotel; provided, further, that (a) such reimbursement obligation shall not duplicate any amounts reimbursed under the Exclusivity Agreement and (b) the aggregate amount of Transaction Expenses reimbursed to DLJMB shall not exceed $5 million. At such time as Trump Taj Mahal is required to reimburse DLJMB for the Transaction Expenses pursuant to the preceding sentence, such reimbursement shall be made promptly based upon the submission by DLJMB to the Company of an invoice for such Transaction Expenses, which invoice shall contain a reasonably detailed breakdown and supporting documentation reflecting any amounts due under such invoice.

2. Transaction Fee. Trump Taj Mahal will become obligated to pay $25 million (the “Transaction Fee”) to DLJMB if, on or prior to December 1, 2004, an Alternative Transaction occurs. The Transaction Fee (if any) shall be earned by DLJMB upon the occurrence of any Alternative Transaction but shall not become payable by Trump Taj Mahal until consummation of any Alternative Transaction without regard to when such Alternative Transaction occurs.

An “Alternative Transaction” will occur when the Company, any of its subsidiaries or any of its controlled affiliates enters into a definitive agreement (including an agreement subject to court approval), files a voluntary plan of reorganization with a court or files an exchange offer registration statement with the SEC, in each case with respect to: