BATS Global Markets, a global operator of securities markets, announced in a release on Tuesday that its president, William O'Brien, has left the company.
CEO Joe Ratterman will reassume his role of President and CEO, a position the release said he had held from June 2007 to January 2014.
None of the other executive management are affected, the company said, without giving a reason for O'Brien's departure. The new roles were apparent on the BATS website immediately following the announcement.
In an April CNBC segment, O'Brien challenged author Michael Lewis and IEX's Brad Katsuyama on their assertion that high-speed traders rigged the markets.
—By CNBC.com. Reuters contributed to this report.