ADDENDUM FOR EMPLOYEES IN CANADA

TAX INFORMATION

         This summary does not discuss all of the tax consequences that may be
relevant to you in your particular circumstances, but is merely intended to
alert you to some of the tax information you may want to consider in making your
decision.

         Although it is not clear, it appears that the tender of eligible
options and subsequent grant of new options will not be a taxable event under
the Income Tax Act. However, the manner in which the Canada Customs and Revenue
Agency will treat this transaction is not certain. It is possible that: (i) a
tax-neutral rollover would be available; (ii) the value of the new options would
be required to be included in your income; or (iii) the eligible options would
be considered to be repriced options, resulting in the loss of the preferential
50% tax deduction and stock option tax deferral treatment ordinarily available
upon the exercise of stock options.

         Please note that tax laws change frequently and vary with your
individual circumstances. Please consult a tax advisor to determine the tax
considerations and tax consequences relevant to your participation in the offer.