"These strategic investments demonstrate BNY Mellon Asset Management's continued commitment to building a world-class stable of investment capabilities to offer investors," BNY Mellon Asset Management chief executive for Australia Bruce Murphy said.
"Both these managers are already actively involved in the Australian marketplace and offer a range of innovative investment solutions."
The London-based Insight Investment specialises in liability-driven investment, fixed income and absolute return products.
The firm is the third-largest manager of United Kingdom pension funds.
Headquartered in New York, Siguler Guff focuses on private equity products in distressed debt and emerging markets.