Taken from the ASIC regulatory guideWhen is substantial holding...

Taken from the ASIC regulatory guide

When is substantial holding disclosure required?
RG 5.292 A person must provide a substantial holding notice if, in relation to an entity
that is a listed company, listed registered managed investment scheme or a
listed body incorporated or formed in Australia, the person:
(a) begins to have, or ceases to have, a substantial holding;
(b) has a substantial holding and there is a movement of at least 1% in their
holding; or
(c) makes a takeover bid for securities of the listed entity: s671B(1).

So looks like Regal can sell bits as long as it remains under 1% of their total holding they do not need to disclose.