PIMCO, the US bond house, has moved quickly to quash market concerns after replacing outgoing CIO Bill Gross with Daniel Ivascyn.

Gross announced last week he was leaving PIMCO to join rival California-based asset manager Janus Capital Management, starting today, and leading an unconstrained bond portfolio next week.

Market reaction was severe as the share price of PIMCO’s German parent, Allianz, plummeted, knocking billions off the insurance giant’s value.

In reverse, the share price for Janus Capital Management soared by 30% as investors anticipated Gross’s move would lead to significant inflows for the asset manager.

Alongside Ivascyn’s promotion to CIO, the firm announced a slight restructure to its investment board, which was initially arranged after the departure of Gross’s heir-apparent and then chief executive Mohammed El-Erian.

In a turbulent year for PIMCO, El-Erian unexpectedly left the firm in January, without reason, leading to a reshuffle at the top with Gross remaining as CIO but supported by several deputies to mitigate what the firm described as “key-man risk”.

Since El-Erian’s departure, the firm and Gross’s flagship Total Return Fund suffered significant outflows.

Now that Gross has the left the firm he founded in 1971, Andrew Balls is now global CIO, Mark Kiesel CIO of global credit, Virginie Maisonneuve CIO of equities, Scott Mather CIO of US core strategies and Mihir Worah CIO of real return and asset allocation.

Douglas Hodge and Lew Jacobs remain as chief executive and president, respectively.

Mather, Kiesel and Worah will now be portfolio managers for Gross’s former Total Return Fund, where he managed more than $200bn (€158bn) in assets.

Saumul Parikh and Mohsen Fahmi join Ivascyn as managers for the Unconstrained Bond Fund.

PIMCO said all changes were effective immediately as Gross begins his new role with Janus later today.

Chief executive Hodge said the succession plan has been in development for some time to help create a seamless transition in the portfolio management team, and they are a continuation of the plan set out after El-Erian’s departure.

“We have passed the torch of leadership to a team of investors who are among the very best in the investment management industry,” he said.

“[The appointments] reflect our long-held belief that the best approach for PIMCO’s clients and our firm is to evolve our investment leadership structure to a team of seasoned, highly skilled investors overseeing all areas of PIMCO’s investment activities.”

Gross sold PIMCO to the Allianz Group in 2000.

Chief executive of the German insurer, Michael Diekmann, wished Gross the best of luck and affirmed its commitment to PIMCO’s leadership team.

“We join our PIMCO colleagues in recognising Bill Gross for his accomplishments over the 43 years since PIMCO’s founding” he said.

“The management and investment structure put in place in January, as well as the thorough succession planning, gives us complete confidence in PIMCO’s investment and executive leadership team.”

Gross will start at Janus today and then take the reins of the recently launched Janus Global Unconstrained Bond Fund and its related offshore fund, to be launched soon.

Based in a new Janus office to be set up in Newport Beach, California, Gross will be responsible for the company’s global macro fixed income strategies.

This will be separate but complementary to Janus’s existing credit-based fixed income platform, which has been built up under Gibson Smith, the company’s fixed income CIO.