Stuart Turnbull has joined Lehman Brothers' fixed income research team as head of US quantitative credit research, reporting to Mark Howard, head of global credit strategy, and to Ravi Mattu, global head of fixed income research.

Within Lehman's fixed income research team, which was named the top research group in 2000 and 2001 in a poll by Institutional Investor magazine, Turnbull will be responsible for overseeing a team of analysts developing innovative credit models. He will also work with the fixed income analytics and technology groups to deploy existing models for the bank and its institutional clients.