Les Rose, president of the Stratis division, was appointed president of the national security group and a vice president of L-3.
Steven Kantor, vice president and president of the services group, will succeed the retiring James Dunn as president of the electronic systems group.
Dunn will retire from the company in December after 12 years with L-3.
Both Rose and Kantor will report to chairman, president and CEO Michael Strianese.
Kantor joined the company in 2003 and served as president of the marine and systems power group between 2008 and 2010.
He also held executive roles at BAE Systems Inc, Loral, Lockheed Martin (NYSE: LMT) and United Technologies.
Rose, who joined the company in 2005, brings management and engineering experience that includes a career with the U.S. Army Corps of Engineers.
Michael Alber and Ray Guillaume recently joined the services group’s executive leadership team, where they will help transition it through a spinoff into standalone firm Engility.