Investors withdrew $7.3bn from the Pimco Total Return Fund in March as the world's largest bond fund continued to stagger six months after the exit of co-founder Bill Gross.
March's outflow marked the 23rd straight month of withdrawals and compared with $8.6bn in the preceding month.
The fund had $117.4bn in assets under management at the end of March, down 60% from a peak of $292.9bn in April 2013.
The Pimco flagship fund is now only slightly bigger than the Vanguard Total Bond Market Index fund, which has assets of $116.8bn, according to Morningstar data.
David Schawel, vice president and portfolio manager of Square 1 Financial told Reuters: "I'm surprised that outflows are continuing this strong as performance has been pretty good.
"Investors seem to be overreacting to the outflows, causing a self-fulfilling cycle. Investors are seeing the outflows and for whatever reason it's causing them concern about being in the fund."
In the three months up to 31 March, the Total Return Fund delivered a net after-fee return of 2.22%, outperforming its benchmark by 61 basis points and generating excess returns of 68 basis points above the Morningstar Intermediate Term Bond Average.
In the six months ending 31 March, the fund returned 3.56%, which was above its benchmark and 90 basis points above the Morningstar category, according to a Pimco statement.
In February, Pimco hired former Morgan Stanley chief economist Joachim Fels as its global economic adviser and a managing director, in a bid to bolster its leadership team.
Pimco had $1.68tn in assets under management as of 31 December 2014.
Pimco, a unit of German insurer Allianz SE, was co-founded by 'bond king' Gross in the 1960s.