Nomura is acquiring Macquarie Group's U.S. and European public asset management businesses for $1.8 billion, marking the Japanese investment bank's most ambitious expansion abroad since its failed purchase of Lehman Brothers' assets.

Nomura Holdings plans to buy Macquarie Group’s public asset management business in the U.S. and Europe for $1.8 billion in a bid to strengthen its investment management business.

Macquarie Asset Management (MAM), part of Macquarie Group, has agreed to divest its North American and European public investments business to Japan’s Nomura in an all-cash deal valued at around $A2.8bn ($1.