Gross, 70, will start Sept. 29 at a new Janus office in Newport Beach, Calif., and will begin managing the Janus Global Unconstrained Bond Fund on Oct. 6, according to a statement from Janus.

"I look forward to returning my full focus to the fixed income markets and investing, giving up many of the complexities that go with managing a large, complicated organization," Gross said in the statement. "I chose Janus as my next home because of my long standing relationship with and respect for CEO Dick Weil and my desire to get back to spending the bulk of my day managing client assets."

Gross is leaving Pimco amid record redemptions at his main mutual fund, the $222 billion Pimco Total Return fund. The firm is also struggling with negative publicity stemming from the abrupt departure of its former chief executive officer, Mohamed El-Erian, which was followed by the biggest management overhaul in its history. Gross's Total Return mutual fund has experienced 16 straight months of redemptions as returns trailed rivals and investors sought alternatives to traditional bond strategies in anticipation of rising interest rates.