The probe is the latest hurdle faced this year by Pimco, which is dealing with record redemptions at its main mutual fund and negative publicity.

Bill Grosss Pimco Total Return ETF is being investigated by the U.S. Securities and Exchange Commission over whether it artificially inflated asset prices to boost returns, according to the Wall Street Journal.

BlackRock Inc. said the corporate bond market, which is one of the cornerstones of global finance, is broken and must be retooled to improve liquidity.