Around 8,000 advisors that make up the two principal US broker-dealers of Morgan Stanley have been merged into one entity, according to the firm.

Morgan Stanley chief executive officer John Mack made it a priority to merge the two broker-dealers since he rejoined the firm in June 2005, according to a spokeswoman.

Morgan Stanley DW was one of the broker-dealer entities involved in the merger that had retained the Dean Witter brand from when Dean Witter, Discover & Co sold to Morgan Stanley in 1997.

At that time Mr Mack was chief operating officer of Morgan Stanley before he left the firm in 2001 to become chief executive of Credit Suisse First Boston, only to rejoin Morgan Stanley as CEO in 2005.

The merger will enhance the integration of products, services and processes across the firm’s various lines of business, the company said.