Northern Trust completed the acquisition of Omnium, the hedge fund administrator, from Chicago-based Citadel for an undisclosed sum at the end of last week.

The financial heavyweight agreed to the purchase, which will add about $70 billion in assets under administration, in May.

Omnium was set up in 2007 and is described as providing technology-driven hedge fund services and middle-office support, access to data which allow real-time monitoring, and support for high volume and highly complex investment strategies.

The new entity will be integrated into the buyer’s corporate and institutional services business unit and be known as Northern Trust Hedge Fund Services. It will offer trade processing, valuation, real-time reporting, cash management, accounting, collateral management, and investor servicing.

In its financial results for the second quarter it released last month, Northern Trust reported that net income had fallen to $152 million from $199.6 million a year earlier.