Morgan Stanley executive Rich Portogallo, who helped build the bank’s prime brokerage business into a Wall Street powerhouse, is retiring after 34 years at the firm, according to an internal memo circulated Wednesday.

Portogallo joined Morgan Stanley in 1986 as one of the first employees of the firm’s then-fledgling prime brokerage business, and over the next two decades helped it become a top competitor, catering to hedge funds and other big trading customers as he rose through the ranks.