30m shares traded post M&G /Vanguard, page-2

20% acquisition limit

Section 606 prohibits the acquisition of a relevant interest in voting shares if, because of that transaction, a person's voting power in the company:

• increases from under 20% to over 20% or
• increases from a starting point that is above 20% and below 90%.

The concept of "relevant interest" is defined in ss608 and 609. Generally, a person will have a relevant interest in securities if they are the holder of the securities, they have the power to exercise, or control the exercise of, a right to vote attached to the securities or they have the power to dispose of, or control the exercise of a power to dispose of, the securities.
A person's "voting power" in a body is determined in accordance with s610. A person's voting power includes the total number of votes attached to all of the voting shares in the company in which that person or an associate has a relevant interest. The concept of "associates" is complex. It will include (a) a person with whom the other person is acting, or proposing to act in concert in relation to the company's affairs and (b) persons with whom they have entered or propose to enter into an agreement for the purpose of controlling or influencing the composition of the company's board or the conduct of the company's affairs. It will also include companies that the person controls or that control the person.
There are a number of exceptions to the prohibition in s606, including:

• an acquisition that results from an acceptance of an offer under a takeover bid (item 1 of s611)
• an acquisition approved by a resolution of the company in which the acquisition is made (item 7 of s611)
• acquisitions of no more than 3% in every 6 months (the 3% "creep" exception in item 9 of s611)
• an acquisition that results from a rights issue (item 10 of s611)
• a downstream acquisition resulting from an acquisition of relevant interests in another listed entity (item 14 of s611) and
• acquisitions resulting from a scheme of arrangement (item 17 of s611).

http://www.takeovers.gov.au/content...mmary_of_takeover_provisions_in_australia.htm