Bidder's Statement (Cash offer by Atacama Copper) - Antofagasta plc

6.3 Option holders who exercise their Tethyan Options and accept the Offer
For those Tethyan Optionholders who hold their Tethyan Options on capital account, and exercise
those Tethyan Options to receive Tethyan Shares, no capital gain or loss will arise from the
exercise of the Tethyan Options. The effect of the exercise of that Tethyan Option is that the
Option will be regarded as having been merged into the Tethyan Share received. The cost base of
the Tethyan Share for CGT purposes will be the amount, if any, paid for the Option, plus the
amount paid on the exercise of the Option. The CGT Treatment for the Tethyan Optionholder
will then be as outlined in the Section 6.2 above.
It is important to note, however, that for the Tethyan Optionholders, the 12 month holding period
for the discount on the capital gains tax starts when the Options are exercised and the Tethyan
Shares are received, not when the Options were granted. For this reason, it is unlikely that the
discount CGT treatment outlined in Section 6.2 above will be applicable to gains arising from the
disposal of the Tethyan Shares acquired as a result of the exercise of Options that are currently on
issue.
Option holders who hold Options issued under the Employee Share Option Plan may have
different taxation implications if they have not previously made the election to be taxed on the
value of the Options at the date of issue. These Option holders are encouraged to seek specific
independent professional advice in relation to their individual position.
In any event, Atacama encourages all Tethyan Optionholders to seek independent professional
advice in relation to their own particular circumstances.
6.4 Stamp duty and the goods and services tax (GST)
No stamp duty or GST is payable by you on the sale of your Tethyan Shares to Atacama pursuant
to the Offer.
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