John Vaske, one of Goldman Sachs’s merger and acquisition co-chairmen, is leaving the firm, according to a memo reviewed by The Wall Street Journal.

A 28-year veteran of the investment bank, Vaske in December was named the third co-chair of Goldman's global M&A group, alongside Tim Ingrassia and Paul Parker. He started in Goldman's M&A department as an analyst in 1988 and became a chemicals banker, and later head of the natural resources group.