I don't think the ACCC will block anything. The QIP + XIP merger...

I don't think the ACCC will block anything. The QIP + XIP merger should be fine. The IPH takeover of XIP should be fine. The reasoning is that there is still plenty of choice in the market for patent attorney/IP services. Only about 173 patent attorneys will be in the IPH-XIP merged group [95+78]. There are still another 1004-173=831 patent attorneys to choose from. Patent attorneys can easily join a new firm or leave the firm they are in. The IPH-XIP merged group does not have dominance to the extent it has pricing power. If it tries to raise prices too high, then it would be logical that clients leave to somewhere else to be serviced quite easily by simply writing a letter to transfer all their cases to the new firm.

The data on patent attorney numbers were taken from:
https://blog.patentology.com.au/2019/03/patent-attorneys-are-leaving-firms-in.html

Assuming I am correct on the ACCC decision, then it would appear there is an arb opportunity. At IPH's current price of $6.725, the value of the offer is $1.99 per XIP share which last traded at $1.83. The QIP off values XIP at $1.84 at QIP's current price of $1.512. In retrospect, the IPH 19.99% blocking stake in XIP really killed off the likelihood of the QIP+XIP merger, and IPH simply needed to capitalise on the advantage and complete its takeover bid.