One of the most highly-regarded bond traders on Wall Street, who joined Morgan Stanley in 2009 to turn around its fixed-income business, has decided to leave the bank after analysts questioned the time being taken to show an improvement in results.

James Gorman, chief executive of Morgan Stanley, said in an internal memo yesterday that Jack DiMaio, global head of interest rate, credit and currency trading, has decided to return to the buyside, where he worked for six years prior to joining Morgan Stanley in 2009.