Both firms are affiliates of Natixis Investment Managers. Loomis Sayles manages $267.3 billion across various assets classes, including equity, fixed income, alternatives and multiasset, and McDonnell runs $11.7 billion in municipal and taxable fixed-income portfolios.
The combination "provides McDonnell clients access to investments backed by Loomis Sayles' extensive research and technology resources, and supplies Loomis Sayles with key strategic municipal capabilities and additional expertise to serve the insurance market," Mark Giura, CEO and chief investment officer of McDonnell, said in a statement in a news release announcing the deal.
For Loomis, the integration will expand its municipal investing capabilities, CEO Kevin Charleston said in a statement in the same release.
Natixis plans to transfer ownership of McDonnell to Boston-based Loomis Sayles on Jan. 1.
Under the deal, the McDonnell municipal portfolio management team "will remain intact," continuing to operate out of its suburban Chicago office in Oakbrook Terrace, Ill. Later next year, management of the firm's core, or taxable, fixed-income strategies will shift to Loomis Sayles' relative-return team, according to the news release.
Mr. Giura will remain leader of the Oakbrook Terrace office and manage the integration with Loomis Sayles.
A Natixis spokesman could not immediately be reached for comment.