A Willow River, Minn., man pleaded guilty Friday to aiding and abetting insurance fraud.

Robert S. Hertz, 65, admitted in Ramsey County District Court that he helped his colleague replace annuities worth about $4.2 million. Six theft-by-swindle counts against Hertz were dropped as part of his plea deal.

According to charges: Hertz and Stephen A. Marrone, 62, worked for Marrone and Associates and BeneVento Capital. The two convinced 19 clients to surrender 52 annuity policies with Allianz Life Insurance of North America between December 2008 and October 2009.

Hertz and Marrone told the clients that a better annuity was available. All they had to do was surrender their current policy and open a new one. The clients incurred a charge for surrendering their policy, but were told that they would receive a 15 to 20 percent bonus on a new investment, the charges said.

Clients believed the bonus would make up for the surrendering charge, the complaint said.

The men applied for 34 "new" Allianz annuity policies for the 19 clients, the complaint said. Allianz dispersed $350,000 in commissions for the policies, with Marrone and Associates and BeneVento Capital earning $317,000.

Marrone is charged with six counts of theft by swindle and one count of aiding and abetting insurance fraud. He has a pre-trial hearing scheduled Jan. 23.

Hertz will be sentenced Feb. 8.

CHAO XIONG