The turbulent second quarter left a big scar on bond king Bill Gross: a record quarterly loss for his bond fund and clients fleeing in droves.

Investors yanked nearly $10 billion in June out of Pacific Investment Management Co.'s $268 billion Total Return Bond Fund (PTTRX) run by Mr. Gross, according to fund tracker Morningstar. The outflow was the biggest cash outflow from the world's biggest bond fund since Morningstar started tracking the fund's flow in 1993.

The outflow came as Mr. Gross's bond fund handed investors a loss of 3.6% in total return basis for the second quarter of the year, the biggest quarterly loss since its inception in 1987, according to data from fund trackers Morningstar and Lipper.

The fund's performance was worse than the 2.32% loss of its benchmark--the Barclays US Aggregate Bond Index, according to Morningstar.

Fund tracker Morningstar reported Tuesday that it estimated Mr. Gross's fund had a net redemption of $9.6 billion in June. But in a release on the monthly flow, Morningstar also noted that Pimco has provided Morningstar with preliminary net cash outflow that was a bit bigger at $9.9 billion. A spokesman from Pimco wasn't immediately available for comment Tuesday.

The June outflow followed a net redemption of $1.32 billion in May from the fund, according to Morningstar. It was the first time Mr. Gross's fund was hit by two consecutive monthly redemptions since the fourth quarter of 2011.

The two-month outflows wiped out the net inflow of $3.45 billion for the first four months of 2013, leaving the fund to post a net redemption of more than $7 billion for the year through the end of June, according to Morningstar.

Write to Min Zeng at Min.Zeng@dowjones.com

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