The group confirmed Olney left her role a few months ago and will not be replaced. On the team, Patrick Schowitz is to continue in his role as European equity strategist and will be supported by Gary Baker, head of international investment strategy.
Meanwhile, Ethan Harris will join the group in September, from Barclays, as head of North America economics, and David Bianco has been recruited as head of US equity strategy.
Harris was chief US economist at Barclays and has also worked at Lehman Brothers and the Federal Reserve Bank of New York.
Bianco was most recently chief US equity portfolio strategist and head of US valuation and accounting research at UBS. He starts in July.
Both will be based in New York and will report to Adam Quinton, head of Banc of America Securities—Merrill Lynch global macro research department.