The $45.9 billion Teachers' Retirement System of the State of Illinois, with $2.4 billion invested through the firm, removed Pimco from its list in May, and the $2.4 billion Sonoma County Employees' Retirement Association did the same in June.

To be sure, the recovery at Pimco still has some way to go.

Big bond rivals BlackRock Inc, Vanguard Group, DoubleLine Capital and TCW Group have been beneficiaries - not only because of the departures of Gross and El-Erian, but also because of Pimco's weak performance in 2013 and 2014. Gross was there for most of that time and El-Erian for more than half of it.

Rivals and analysts say they are not yet convinced that Pimco has turned the corner.

"It is too early to make a judgment on Pimco," said Jeffrey Gundlach, the co-founder of DoubleLine, which oversees $76 billion in assets. "Less than one year is too early for any investment strategy. But I do think it would behoove them to clarify their investment process absent Bill Gross," he said referring to a sense that the firm is no longer transparent about the way it operates.

Gundlach's DoubleLine posted its 17th consecutive month of cash inflows in June and the Los Angeles-based firm has hired six Pimco employees since April 2014.

Todd Rosenbluth, head of exchange traded fund and mutual fund research at S&P Capital IQ, said Pimco "will need to continue to generate strong risk-adjusted returns for a more extended period of time for more investors to pay attention and to look to restart inflows."

Pimco faced another headache on Monday. The firm said it may face U.S. Securities and Exchange Commission civil charges over a smallish exchange-traded fund once managed by Gross.

Pimco, a unit of Germany's Allianz SE, said the SEC is looking at whether Pimco Total Return Active Exchange-Traded Fund properly valued small stakes in non-agency mortgage-backed securities it bought from its Feb. 29, 2012 inception to June 30, 2012, leading to inaccurate disclosures about the fund's performance.

Overcoming The Short-Term Plan