An announcement of the fines, expected to be levied against Alexander Clay & Partners, Godwins, CE Heath, Sedgwick and Willis Corroon, is likely to be made next week.
The regulator is also expected to gag the companies from giving their own view of how the offences were committed.
This is said to be the brainchild of Dan Waters, director of monitoring and enforcement at Imro, who was recruited from the US Securities and Exchange Commission.
The fines, which follow a year-long investigation into pensions mis-selling by former and existing Imro members, are the heaviest penalty to be imposed by any regulator.
Imro's investigation into 22 firms, many of which transferred into the Personal Investment Authority two years ago, found that about 77,000 pension transfers were carried out by them. Of these, the five firms whose fines are expected to be announced next week carried out about 25,000 transfers. It is thought, however, that only a minority involved bad advice.
A Imro spokeswoman last night refused to comment on the fines. She said the regulator did not impose gagging orders. It expected a firm that had admitted an offence and was fined to abide by that admission and not try to deny or minimise it afterwards.Reuse content