BlackRock Inc., the world’s largest money-manager, named Rich Kushel to head multi-asset strategies and Tim Webb to oversee global fixed income in its third reorganization since 2012.

Ken Kroner, who led both the multi-asset strategies and scientific active equity business, will retire later this year, according to a memo provided by the firm. Philipp Hildebrand, currently chairman of multi-asset strategies, will lead the BlackRock Investment Institute. BlackRock will also combine its fundamental and scientific active equity groups, and set up a new real assets group.

Chief Executive Officer Laurence D. Fink, 63, and President Robert Kapito, 57, have previously promoted younger executives to senior roles after a number of the firm’s co-founders left or retired from active positions. In 2012 the firm added eight members to its global executive committee and made changes to its investment unit to improve returns. Two years later, BlackRock expanded its senior management by giving at least 10 senior executives new roles.

"We have regularly moved senior leaders into new roles, as we did in 2012 and 2014, with very positive benefits for them, the firm and our clients," according to the memo.

Kushel, currently chief product officer and head of strategic product management, will report to Kapito in his new role. Rick Rieder, currently chief investment officer of fundamental fixed income, will become CIO of global fixed income. The changes are effective Feb. 1.

BlackRock expanded from a bond shop started in a one-room office to a $4.5 trillion global money manager with much of the growth fueled by acquisitions, including the 2009 purchase of Barclays Plc’s investment unit. Susan Wagner, a co-founder who helped lead the acquisition push, retired in 2012 when the firm reached a size that made significant deals difficult. Ralph Schlosstein and Keith Anderson are among other co-founders that are no longer with the firm.