Atlanta-based Invesco Inc. will acquire OppenheimerFunds, Inc., an affiliate of Springfield, Mass.-based Massachusetts Mutual Life Insurance Co. (MassMutual), the companies announced Thursday.

In turn, MassMutual will become a significant shareholder in Invesco, with an approximate 15.5% stake.

Invesco is the parent company of Toronto-based investment fund manager Invesco Canada Ltd.

The Oppenheimer transaction will bring Invesco’s total assets under management  to more than US$1.2 trillion, making it one of the largest global investment managers.

“The combination with OppenheimerFunds and the strategic partnership with MassMutual will meaningfully enhance our ability to meet client needs, accelerate growth and strengthen our business over the long term,” says Martin Flanagan, president and CEO of Invesco, in a statement.

“This is a compelling, highly strategic and accretive transaction for Invesco that will help us achieve a number of objectives: enhance our leadership in the U.S. and global markets, deliver the outcomes clients seek, broaden our relevance among top clients, deliver strong financial results and continue attracting the best talent in the industry.”

The companies expect the deal to close in the second quarter of 2019, pending necessary regulatory and other third-party approvals.