Sullivan & Cromwell and Simpson Thacher & Bartlett have landed lead roles on a deal that will see Primus Financial acquire a 70 percent stake in municipal bond broker Chapdelaine. Financial terms of the deal were not disclosed.

Robert Morse, Citigroup’s former chief of Asian institutional banking, set up Primus almost a year ago. Since then, the Hong Kong-based investment firm has recruited several former top Citi executives while seeking to build a financial services firm through acquisitions — particularly in distressed financial assets.