Investment Technology Group said Monday that it has replaced chief executive Bob Gasser with board member and E*Trade Financial veteran Jarrett Lilien, after disclosing a possible dark pools settlement with the Securities and Exchange Commission last week.

"We are very pleased that Jarrett has agreed to serve as interim CEO, while we consider our options for a permanent CEO," said Maureen O'Hara, chairwoman of ITG's board. Lilien was chief operating officer and president at E*Trade.