The move is one of a series being considered by regulators and industry bodies on both sides of the Atlantic as they discuss banning sell-side research.

Most fund managers pass on the cost of (about $5 billion a year) to their own clients, who pick up the bill as part of a brokers’ commission for buying and selling stocks on behalf of the fund.

But as regulators step up efforts to police potential conflicts of interests between asset managers and investment banks, firms could soon be forced to pay for any research they require out of their own pocket.

Using data from publicly-listed international asset managers, Frost Consulting and financial software provider Quark estimate that operating margins for actively-managed equity funds will fall to 12.5 per cent from 23.5 per cent.

Active equities accounts for between 20 per cent and 100 per cent of an asset manager's business depending on the scope and scale of their company offering.

"The old model of having the research paid for in part by commissions is being eroded and if they were forced to cover the whole cost of the research they use, it would have very significant impact on profitability," said Neil Scarth, principal at Frost Consultants.

"Asset managers are under pressure to provide greater transparency and accountability in terms of how they pay for the equity research they receive," Scarth added.

Sell-side research is a hot topic, as the London-based trade body the Investment Management Association is due to publish a report on how asset managers pay for equity research next month following all the regulatory attention.

Earlier this year, Britain's Financial Services Authority, now the and the Prudential Regulatory Authority, wrote to asset management firms to flag concerns about how they run their operations. In this respect, a key concern was firms failing to control the amount of customer money spent on research and trading services or conduct regular reviews on whether services were eligible to be paid out of customer commissions.