Pimco said on Friday Paul McCulley had stepped down as chief economist and as a managing director, a role he had assumed in May at the request of Bill Gross, who was the investment firm’s chief investment officer at the time. The move comes just 10 days after Pacific Investment Management Co hired former Morgan Stanley chief economist Joachim Fels as its “global economic adviser” and a managing director, an appointment that raised questions about McCulley’s role at the Newport Beach, California-based firm, a unit of German insurer Allianz SE.