The National Association of Securities Dealers has issued a cumulative $7 million fine to four US brokerages affiliated to the North American operations of Dutch financial services firm ING.

The fund brokers, who are affiliated to ING America Insurance Holdings, were fined for taking fees and commissions in exchange for giving preferential treatment for certain mutual fund companies, the Dow Jones has reported.

The broker-dealers in question are Financial Network Investment Corp, ING Financial Partners Inc., Multi-Financial Securities Corp. and Prime Vest Financial Services.

The four firms were fined: $3.42 million, $1.29 million, $1.23 million and $1.07 million respectively. However, none of the companies have admitted the allegations.