(Reuters) -Exchange operator Nasdaq said on Monday it was investigating issues related to the matching engine that was impacting connectivity to the exchange.

Matching engines are software systems that match buy and sell orders on an exchange.

The company said orders sent using the "RASH FIX" order handling system will not being acknowledged at this time. Nasdaq first alerted customers about the issue on its website, at 4.55 a.m. Eastern Time.

Nasdaq did not immediately respond to a Reuters request for comment.