Bill Gross, one of the best known fixed income investors in the world, will retire from Janus Henderson to focus on managing his charitable foundation, the firm said Monday.

Gross, 74, joined Janus Henderson in 2014 after co-founding Pacific Investment Management Company, better known as PIMCO, in 1971. He served as managing director and chief investment officer until leaving the Newport Beach, California-based group nearly five years ago. Gross will leave Janus on March 1. 

"I've had a wonderful ride for over 40 years in my career - trying at all times to put client interests first while inventing and reinventing active bond management along the way," Gross said. "So many friends and associates at my two firms to thank - nothing is possible without a team working together with a common interest. I've been fortunate to have had that."

"And thank you to all of my past clients for their trust and support," he added "I learned early on that without a client, there can be no franchise. I'm off - leaving this port for another destination with high hopes, sunny skies and smooth seas!"

Gross ran the Global Unconstrained Bond and Total Return strategies at Janus, which allowed investors to put money to work across the spectrum of fixed income investments in order to generate maximum returns.

However, his Janus Henderson Global Unconstrained Bond Fund has generated returns of -6.9% over the past year, in part due to persistently low government bond yields in Europe, where Gross had bet on rate increases, and similar dynamics in the United States.

"While the Unconstrained strategy Mr. Gross manages has underperformed its 3-month Libor benchmark since Mr. Gross joined Janus Henderson in late 2014, nominal performance has been positive over the time period," Janus said in a statement Monday. "In addition, and in-line with Mr. Gross's career success as a bond investor, his currently existing Total Return strategy has outperformed its U.S. Aggregate benchmark by 89 basis points, net of fees, through 12/31/2018."

The poor performance, however, took the fund from a peak of $2.2 billion in assets last year to just over $950 in January, according to a report from the Financial Times, a far cry from the near $300 billion Gross managed at the apex of his career with PIMCO's Total Return fund.

Nick Maroutsos, the current co-head of Global Bonds and portfolio manager at Janus Henderson, will take over Gross' fund effective February 15, the company said, but will change its name to the absolute return income opportunities fund.