Investors yanked $7.3 billion from the Pimco Total Return Fund in March as Pimco's flagship fund continued to reel six months after the exit of co-founder Bill Gross.

March's outflow, reported by Pimco on Thursday, marked the 23rd straight month of withdrawals, and compared with $8.6 billion the previous month. The fund had assets under management of $117.4 billion at the end of March, a 60 percent drop from a peak of $292.9 billion in April 2013.

The Pimco Total Return Fund remains the world's largest bond fund, although it is now only slightly bigger than the Vanguard Total Bond Market Index fund, which has assets of $116.8 billion, according to Morningstar data.

Improving portfolio performance since Gross's sudden departure on Sept. 26 has been overshadowed by the net cash withdrawals.

"I'm surprised that outflows are continuing this strong as performance has been pretty good," said David Schawel, vice president and portfolio manager of Square 1 Financial. "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 first three months of the year, the Pimco Total Return Fund delivered a net after-fee return of 2.22 percent, 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 March 31, the fund returned 3.56 percent, which was above its benchmark and 90 basis points above the Morningstar category.

In an interview with Reuters last month, 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 February, Pimco hired former Morgan Stanley chief economist Joachim Fels as its global economic adviser and a managing director.

And last month, Ben Bernanke, the former Federal Reserve chairman, participated in Pimco's Cyclical Forum at its headquarters in Newport Beach, California. It was Bernanke's second appearance at Pimco's forum following his December attendance.