Acadia, page-214

@WESTHOT is right. If scrip for scrip is available, you retain the initial purchase date and cost base of the investment in company A and defer the capital gain on the takeover transaction until you sell the shares in company B. You can't defer a capital loss but that doesn't make any difference.

So in short, you would still be entitled to the CGT discount if you have held the shares in company A for more than 12 months and only report the capital gain once you sell shares in company B. Scrip for scrip is not always available though but with listed companies, there usually is an ATO ruling.