May 14 (Reuters) - Steelmaker Nucor said on

Wednesday it had halted certain production at various locations

after identifying a cyber security incident that involved

unauthorized third-party access to certain information

technology systems it used.

The Charlotte, North Carolina-based company said it is in

the process of restarting the affected operations as it

investigates the incident along with external cyber security

experts.

Nucor ( NUE ) has notified federal law enforcement authorities

and is taking the potentially affected systems offline, while

also implementing other containment, remediation or recovery

measures, it said in an SEC filing.