The offer document for the shares, which are expected to start trading next month, was made public on Friday.

Shares are likely to be priced between $2.35 and $2.80 and there have been suggestions that uncertainty over Rio Tinto’s plans for Tiwai Point may push the price to the lower end of that scale.

But investors will nominate a dollar amount they wish to purchase, not a number of shares, so if there are a lot of would-be purchasers, the share price may be pushed up.

PAA chairman Peter Leitch said most potential purchasers would have to get their information from the media, because advisers were hamstrung by regulation. “Advisers can’t really comment. People have got to read the prospectus and make their own decisions.”

He said that whereas in the past, a client might ring an adviser and ask for an opinion, now regulation required that advisers go through the full advice process in order to make any comment. “I can’t tell them whether they are right to buy shares. I would need to say ‘we need to have a meeting’. It’s better just to say I don’t do that.”

Leitch said it was safer for media commentators to give their opinions than it was for financial advisers to weigh in. “It’s the first share float where a lot of people have expressed interest and they will want reassurance, they will call people like me and I kind of can’t say anything.”