Eighth Amendment and Limited Term Waiver Agreement

QuickLinks -- Click here to rapidly navigate through this document

Exhibit 4.29

EXTENSION OF WAIVER TERMINATION DATE

February 14, 2005

Inter-American Development Bank
Private Sector Department
1300 New York Avenue, N.W.
Washington, D.C. 20577
Attention: Loan Administration Unit

Export Development Canada
151 O'Connor Street
Ottawa, Ontario
Canada
K1A 1K3
Attention: Special Assets Unit

Ladies and Gentlemen:

        Reference is made to the Eighth Amendment and Limited Term Waiver Agreement dated as of February 13, 2004 (the " Eighth Amendment ") between among SR Telecom Inc., a corporation duly organized and validly existing under the laws of Canada (" SRT "), Comunicación y Telefonía Rural S.A., a sociedad anónima duly organized and validly existing under the laws of Chile (the " Borrower "), Export Development Canada (formerly Export Development Corporation), a corporation established by an Act of the Parliament of Canada (" EDC "), and Inter-American Development Bank, an international organization established by the Articles of Agreement among its member countries (" IDB ", together with EDC, the " Senior Lenders "). Capitalized terms used herein and defined in the Eighth Amendment shall have the same respective meanings herein.

        Pursuant to Section 6 of the Eighth Amendment, the Eighth Amendment will expire upon the earliest date of occurrence of any of the events listed therein. Section 6(a) of the Eighth Amendment lists February 14, 2005 as one such event. In view of the fact that the parties hereto continue to review the terms of documentation related to a secured debt facility to be entered into by SRT, which transaction will require the consent of the Senior Lenders and the final terms of which are anticipated to materially impact the scope and terms of such consent, each of the parties hereto agree, subject to the conditions specified in the last paragraph of this letter, that:

        (1)   Section 6(a) of the Eighth Amendment is hereby amended in its entirety to read as follows:

        "(a) March 31, 2005;";

        (2)   Section 6(h) of the Eighth Amendment is hereby amended in its entirety to read as follows:

        "(h) the date that (i) any secured creditor of the Borrower or SRT initiates steps to, or notifies the Borrower or SRT of its intent to, foreclose on any assets of the Borrower or SRT, with respect to which such creditor holds a Lien or (ii) the Senior Lenders shall have provided written notice to the Borrower following the initiation by any creditor of SRT of a suit or proceeding against SRT for the payment of an amount in excess