Aerotek promoted Todd Mohr to president from his previous position as chief operating officer. Mohr will oversee Aerotek’s operations at its more than 200 offices in North America and Europe.

Mohr has worked for Aerotek and its parent company, Allegis Group, since 1995. He began as a technical recruiter at Aerotek.

Mohr’s predecessor, Thomas Thornton, will remain active with the Allegis Group board of directors.

Allegis Group ranks as the largest staffing firm in terms of U.S. staffing revenue, according to the 2011 list of largest U.S. staffing firms by Staffing Industry Analysts.