It appears the ASX published guidance in 2016 contradicts what is happening now, the 75% control or ownership was "likely" required back then, now not required.
Takeover bid by TIO (NZ) Limited for Flinders Mines Limited 31 March 2016
Page 31, Corporate Matters (4)
"If delisting is sought, TIO expects that a final decision as to Flinders’ removal will be made by ASX in accordance with its published guidance. This states that it is generally acceptable for an entity to be delisted if, as a result of a takeover, the entity only has a small number of remaining security holders so that its continued listing can no longer be justified. ASX does not prescribe a minimum shareholding that the bidder must have, or a maximum number of remaining shareholders, before it will sanction a delisting, but its published guidance states that it will likely require shareholder approval be obtained unless (among other things) the bidder and its related bodies corporate own or control at least 75% of the entity’s ordinary securities, and there are less than 150 minority holders of ordinary securities with holdings with a value of at least $500."
