Further details reported by Sky News suggest the three firms could join Schroders and M&G in heading in a different direction.
Spokespeople for Invesco, Fidelity and Aberdeen declined to comment.
A spokesperson for the IA said the statement issued by CEO Daniel Godfrey in which he said he would be ‘incredibly disappointing to lose any member’ still stands, without making further comment.
The IA directors are due to meet today, Tuesday 6 October, where they will have the opportunity to discuss the situation.
While the prospect of losing some of the biggest firms is a major concern for the IA, it does not necessarily follow that there would be a wide ranging exodus.
Skagen Funds for example, told Portfolio Adviser it remains committed to its membership.
