You need to be a bit more specific. Are you talking about shares held in a company that has been taken over and the shares were held by you for less than 12 months before the takeover?
Usually when there is a take-over, there will be some sort of document produced that indicates the status of shares held in the company and the tax implications. For instance, were you paid out in cash for your shares or were you allocated shares in the new company in exchange. If paid out in cash then unless told otherwise, that would be the same as any capital gain on shares held for less that 12 months (taxed fully at your marginal rate). However in the case that you were given shares in the acquiring company in exchange for your shares in the acquired company, they often come to some arrangement with the ATO that treats the exchange of shares as not being a capital event with the new shares deemed to have been acquired at the time the original shares were acquired. As I said, you should have received some documentation about the tax implications of the take-over. If not, perhaps you should post the companies involved and someone here may be aware of what took place.
