A Des Moines, Iowa, insurer has agreed to acquire ABN AMRO Trust Services Company, Chicago.[@@]

ABN AMRO Trust helps run more than 300 401(k) plans with a total of about 121,000 plan participants and $3.6 billion in account value.

The acquirer, Principal Financial Group Inc., says it is making the deal to expand its asset-accumulation business.

The seller, ABN AMRO Holding N.V., Amsterdam, says it is selling because ABN AMRO Trust no longer fits well with its plans.

Principal and ABN AMRO hope to complete the deal by Dec. 31.

The companies are not giving the price of the deal, but Andrew Kligerman, an analyst at UBS Investment Research, New York, says he believes the price is less than $50 million.

“It is our understanding that the deal was also priced to earn higher than 17% to 18% returns, which is what PFG’s full-service accumulation business is currently generating,” Kligerman says.