The regulators of the Australian Stock Exchange are being taken for a ride by more and more listed companies as the silly takeover frenzy intensifies.

We now have regular examples of companies engaged in talks without disclosing them to the wider market, only for the news to emerge and enable some players in the market to grab some nice fat profits.

The Promina-Suncorp merger news was out and about, possibly as early as 29 September, when a sudden surge in trading in one particular Promina option contract was identified. There was another surge in the same contract earlier this month before the news leaked out last Wednesday/Thursday and the ASX forced both companies to make a statement.

But the most egregious example is that of the printing firm PMP. It was queried last week about a 17% rise in the share price from 6 October to 11 October and it replied that it had been approached by a private equity group.

Then yesterday the ASX lobbed the same query in and someone must have twigged at PMP that the exchange was asking a VERY serious question, because the level of disclosure suddenly lifted.

Now we were told that PMP was approached back in March and April of this year by an unnamed private equity group.

And fancy not telling shareholders and the market that you’d appointed Gresham Partners and Blake-Dawson Waldron to “protect shareholder interests and maximise shareholder value”.

It resembles the case of Colorado group, which appointed Gresham Partners without explanation in the middle of this year. It later emerged that the board had been talking to private equity group, Affinity Equity Partners of Hong Kong. Affinity is still trying to take Colorado private but Solomon Lew has a 10.1% blocking stake.

Why didn’t PMP tell all last Thursday in reply to the first query from the ASX, even if the talks are at an early stage?

The company’s shares bounced 17% to reach $1.76 on 11 October (from $1.49.5c on 6 October. It closed at $1.85.5c yesterday, down 1.5c on turnover of 1.565 million. That’s hardly a vote of confidence in the buyout by punters and other speculators.

For PMP to be queried twice by the ASX about the same price movement, and to provide two different answers, the second of which should have been disclosed last week, bears more examination by the regulators.