His role will include oversight of some of Hearst's 29 stations and assisting Barrett in other duties at company headquarters in New York.
Since 2005, Wertlieb has been the chief of Hearst-owned WBAL, the NBC affiliate in the country's 26th-largest market. The 46-year-old has been with the Hearst group for 17 years, first in Boston and then Baltimore.
In his early 60s, Barrett has been CEO for 10 years and sits on the 13-member board that oversees Hearst Corp., which includes the large magazine operations. He also served as head of WBAL several decades ago.
"(Wertlieb) has great passion, energy and enthusiasm for our company and our industry," Barrett stated. "And his business acumen and smart strategic insights -- applied more broadly across our company -- will help us address future challenges and the exciting next generation opportunities."
Wertlieb began at Hearst in 1993 at WCVB in Boston, where he rose to local sales manager. He moved to WBAL as general sales manager before rising to become its general manager.
During his tenure as station head, he worked with Hearst's two Baltimore radio stations to craft partnerships with the Baltimore Ravens, Maryland Lottery and Maryland Special Olympics.
Hearst operates 29 stations that reach about 18% of U.S. homes. It is the largest ABC affiliate group and second largest for NBC.
At times, Barrett was an outspoken critic of network performance when Hearst Television was a stand-alone public company and he held earnings calls. Several years ago, it became a division of the privately held Hearst Corp.