Bear Stearns' chief investment strategist has left the bank to join an investment research firm as head of portfolio strategy and quantitative research.

Francois Trahan, a top-ranked portfolio strategist at Bear Stearns, has joined ISI, an investment research firm, broker- dealer and fund manager. He will be responsible for coordinating ISI's work in economics, integrated oil research, China research, policy research, tech strategy and company surveys.