Backup cooling capacity has been installed at CyrusOne's Chicago, Illinois, data center that suffered an outage.

Last week, a chiller plant failure at the CHI1 data center meant that leaser CME Group was forced to halt futures trading.

The world's biggest exchange operator experienced a multi-hour outage, which halted trading of stocks, bonds, commodities, and currencies.

“CyrusOne has restored stable and secure operations at its Chicago 1 (CHI1) data center in Aurora, Illinois,” the company said.

“To further enhance continuity, we have installed additional redundancy to the cooling systems.”

CyrusOne acquired the data center from CME in 2016 for $130 million. Owned by KKR & Co. and Global Infrastructure Partners, CyrusOne operates 55 data centers.