"The media industry is rapidly evolving, increasingly global, more consumer-focused and more multi-platform, and Discovery must evolve with it", Laslav said in a statement.
Pending the closing of its Scripps acquisition, Zaslav told employees Discovery plans to create a national operations headquarters in Knoxville, and a technology hub at its Sterling, Virginia facility.
Montgomery County Executive Ike Legget announced Tuesday he was "disappointed" to hear of the decision by Discovery Communications to move its headquarters from downtown Silver Spring.
The specific location for the New York City headquarters is still under planning, but the move is expected to be completed in the second half of 2019.
The new company headquarters will be in NY, according to the memo.
In addition to the Discovery, the company runs other TV networks including Animal Planet, TLC, Investigation Discovery and OWN. The deal was announced in July 2017 and is expected to close in mid-2018. The company had said at that time that it would be moving 230 employees from their Kennett Street creative and technical center to their main building.
The company, which employs 1,300 people in the Silver Spring area, has been at their location at Wayne and Georgia Avenue at 1 Discovery Place for 15 years.
Zaslav's memo also said, "This was one of the toughest calls we have made in our company's history, and we do not take it lightly". Discovery also recruits interns regularly from nearby schools like the University of Maryland and Johns Hopkins University. A Maryland Network Hub is planned to house select functions, such as government relations and Discovery Education.
Discovery received $10 million to move its headquarters from Bethesda to Silver Spring, where it helped spark redevelopment.