Retirement plan provider Transamerica Corp. has agreed to pay $3.8 million to settle a class-action lawsuit over the fees it charged participants in its own 401(k) plan.

Participants alleged Transamerica’s parent company Aegon collected $40 million by charging “layers of superfluous fees” for investment management and other services. An Iowa judge approved the settlement of the ERISA class action last week.

Transamerica’s 401(k) plan had 16,715 combined participants and deceased participants with beneficiaries receiving benefits and held $1.56 billion in assets at the end of the 2013 plan year. According to the suit, which was filed in February 2015, Aegon managed the plan “to benefit itself, in breach of its fiduciary obligations under ERISA, by burdening the Plan with layers of superfluous fees paid to Aegon affiliates.”

Among other things, the suit alleged, Aegon portfolio managers charged a “substantial” investment management fee even though they simply picked an underlying Aegon mutual fund in which to invest plan assets. At least 16 Aegon collective investment trusts or pooled separate accounts were offered in the plan.

In addition, the company allegedly charged an advisor fee “merely for picking a subadvisor to do all the real work of portfolio management.

“Mega plans,” those having over $1 billion in assets, have a median total fee of 30 basis points, or .30%, including management fees, administrative fees and other insurance charges, according to the suit. The Aegon plan had average fees each year of more than 160 basis points, or 1.6%, on management investment fees alone, the suit said.

“Transamerica joins a growing list of retirement plan service providers that have been targeted in similar excessive-fee lawsuits by their plan participants,” InvestmentNews reported.

Earlier this month, Massachusetts Mutual Life Insurance agreed to settle with its employees for $31 million, while Fidelity Investments and Ameriprise Financial have recently paid out $12 million and $27.5 million, respectively.