Natixis Global Asset Management said Tuesday that it has agreed to acquire McDonnell Investment Management, an Oak Brook, Ill.-based investment adviser with $13.5 billion under management for institutions and individuals.

Terms of the deal were not disclosed, said Natixis, which has headquarters offices in Boston and Paris.

McDonnell specializes in fixed-income investments. Natixis has a total of $711 billion under management and brands including Loomis, Sayles & Co. in Boston.