Don Putnam, co-founder of Putnam Lovell NBF, the investment banking boutique, has left the firm three years after its takeover by National Bank Financial of Canada.

Putnam, 53, was chief executive at the firm, which is renowned for the M&A advice it gives asset managers. He is said to be setting up an advisory boutique called Grail Partners. Putnam was involved in some of the biggest fund management mergers of the 1990s.