Lowell C. McAdam, the current chief executive, was retiring and that Hans E. Vestberg, the chief technology officer, will succeed him on August 1 2018. Mr. McAdam, who served six years in the Navy’s Civil Engineer Corps before embarking on his career, was named Verizon's CEO on August 1, 2011, and Chairman on January 1, 2012.After leaving his post on Aug. 1, Mr. McAdam, 64, will continue as Verizon’s executive chairman until he retires at the end of the year, the company said.