A person familiar with the matter says a formal letter was sent this week. The person wasn’t authorized to speak publicly and requested anonymity.
It comes after the revelation Friday that Bloomberg reporters had special access to client usage data and sought to use it to break stories. On Monday, Bloomberg News Editor-in-Chief Matthew Winkler apologized for the practice.
That special access for journalists was cut off last month after Goldman Sachs complained.
A Bloomberg spokeswoman declined comment.