February's outflow, the 22nd straight month of withdrawals, compared with $11.6 billion the previous month. The fund had assets under management of $124.7 billion at the end of February, down from a peak of $292.9 billion in April 2013.

In an interview with Reuters on Tuesday, Pimco Group Chief Investment Officer Dan Ivascyn said: "We expected some of these (outflows) to ripple through the new year."

Pimco, which had $1.68 trillion in assets under management as of Dec. 31, has been aggressively trying to reassure clients through meetings, conference calls and advertisements that the firm remains committed to the same investment strategies.

It also has been bolstering its leadership ranks over the last year since the departure of former Chief Executive Mohamed El-Erian, the result of a falling out over Gross' leadership style and investment strategy.

In the five month period ending Feb. 28, the Pimco Total Return posted returns of 3.25 percent, or 0.30 percentage point above the benchmark, and 0.90 percentage point above its Morningstar intermediate peer category.

"The departure by Bill Gross continues to negatively impact Pimco Total Return," said Todd Rosenbluth, director of ETF & Mutual Fund Research at S&P Capital IQ.

"Again, this is a slow, drawn-out bleed where institutions change managers after much debate. Outflows for Pimco are likely to continue in the months to come given decisions for some were put off from pension funds, foundations and endowments."

(Reporting by Jennifer Ablan; Editing by Dan Burns and Andre Grenon)

By Jennifer Ablan