David Tripple, CEO of Pioneer Investments, will step down Sept. 30...

David Tripple, CEO of Pioneer Investments, will step down Sept. 30 after 27 years with the company. Mr. Tripple is leaving for personal reasons, said Denise Robbi-Arena, Pioneer spokeswoman. A new CEO is being sought, but Ms. Robbi-Arena did not know whether one would be named before Mr. Tripple’s departure. Pioneer was purchased by UniCredito Italiano last year.