By Chelsey Dulaney 

Pacific Investment Management Co. said Friday that Paul McCulley will step down as managing director and chief economist at the end of the month, less than a year since returning to the firm last May.

Mr. McCulley returned to Pimco after being recruited by Bill Gross, a close friend and the firm's co-founder and Total Return manager.

Mr. Gross shocked the finance world by leaving the firm at the end of September to start a new mutual fund at Janus Capital Group Inc. Newport Beach, Calif.-based Pimco has since scrambled to keep investors following months of internal strife.

Mr. McCulley's last day at Pimco will be Feb. 28.

Pimco, a unit of German insurer Allianz SE, also lost its chief executive, Mohamed El-Erian, last year after clashes with Mr. Gross.

In January, investors pulled another $11.6 billion from Pimco's flagship Total Return fund as retirement plans withdrew more commitments from the world's largest bond mutual fund.

The new outflows were lower than the $19.4 billion lost in December, according to the company. But January was the 21st consecutive month of withdrawals from the company's flagship fund, according to research firm Morningstar Inc. It is now down 54% from its peak of $293 billion in April 2013.

Write to Chelsey Dulaney at Chelsey.Dulaney@wsj.com

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