Exhibit 8

                                                            Terence H. Matthews
                                                             [address redacted]

May 1, 2006

Personal & Confidential - By Hand

Mr. Peter D. Charbonneau
[address redacted]

Dear Peter,

The purpose of this letter agreement (the "Agreement") is to confirm and
formalize the material terms of our oral agreement made February 16, 2001
wherein I granted to you the option to purchase 900,000 common shares of Mitel
Networks Corporation ("Mitel") in recognition of services performed by you, at
my request, during the transaction that resulted in the spin off of Mitel from
Zarlink Semiconductor Corporation (the "Services").

By signing this Agreement, you and I agree that the material terms of our
agreement are as follows:

     o    I, Terence H. Matthews, on February 16, 2001 (the "Grant Date")
          granted to you an option to purchase 900,000 common shares of Mitel
          from Wesley Clover Corporation, or if agreed between us at the time
          of exercise, from my direct or other indirect holdings of Mitel
          common shares, at an exercise price of CDN$3.50 per share;

     o    the options shall expire ten (10) years from the Grant Date;

     o    the options are fully vested as of the date of this Agreement,
          however, the options are not exercisable prior to the completion of a
          Qualified Initial Public Offering, as that term is defined in the
          Shareholders Agreement dated April 23, 2004; and

     o    the options are not assignable or transferable by you or subject to
          any other alienation, sale, pledge or encumbrance by you except by
          will or by the laws of decent and distribution. Your obligations
          under this Agreement shall be binding on your heirs, executors and
          administrators.

This Agreement constitutes the entire understanding and agreement between us
regarding your compensation for the Services. There are no other understandings
or representations, whether written or oral, express, implied or collateral,
between the parties with respect to the subject matter hereof.



Please confirm your acceptance of the terms and conditions set out in this
Agreement by signing below and returning to Jose Medeiros a signed copy of this
Agreement at your earliest convenience.

Yours truly,

/s/ Terence H. Matthews
---------------------------
Terence H. Matthews


Acknowledgement and Acceptance

I, Peter D. Charbonneau, have read and reviewed, in its entirety, this
Agreement. I confirm that the Agreement constitutes the entire understanding
and agreement between Terence H. Matthews and myself regarding my compensation
for the Services, and I accept the terms and conditions set out above.

May 4, 2006                                            /s/ Peter D. Charbonneau
                                                       ------------------------
                                                       Peter D. Charbonneau