The departures include Reuters Media President Chris Ahearn and Investment & Advisory President Eric Frank.
Thomson Reuters stock was down 3.6 percent in afternoon trading on the New York Stock Exchange, as the departure of Wenig -- announced late on Thursday -- spurred concerns about the performance of his unit, which serves financial institutions.
The Markets division is being reorganized, after growth has been "somewhat slower than anticipated" in the second quarter, the company said on Thursday.
The other senior executives leaving are Markets Global Sales and Customer Service Managing Director Joerg Floeck, Markets Chief Marketing Officer Lee Ann Daly and Markets Global Head of Human Resources John Reid-Dodick, the company said in a memo to employees on Friday.
(Reporting by Jennifer Saba, editing by Ted Kerr)