Technical issues at CME Group (CME - Get Report) halted trades late Tuesday into Wednesday in some global financial instruments, including U.S. Treasury futures and the S&P 500 futures.

The outage affected many markets including metals, grains, crude oil and natural gas. According to data from Bloomberg, no trades were executed in U.S. stock-index futures since early Wednesday in Asia.

CME acknowledged that "due to technical issues, all CME Globex markets have been halted." An announcement on the group's website about 9 p.m. Eastern on Tuesday read: CME Group has identified the technical issue and is working to resolve it. When the iLink gateways are restarted they will be in the normal primary/backup configuration. We will publish the pre-open and opening times shortly."