Investment manager Grantham, Mayo, Van Otterloo (GMO) has agreed to purchase Usonian Investments, a value-oriented Japan equity manager that manages over $1bn.

Financial terms of the transaction were not revealed.

Customers of GMO will have access to the Usonian strategy as a new standalone proposition.

The offering will be available as a complementary investment within GMO Asset Allocation portfolios.

GMO has also made several senior appointments separate for the purchase of the equity manager.

These include the appointment of QMA CIO Roy Henriksson as the head of investment risk and trading.

He will assume the new role, which is a newly created one, in October.

In the new role, he will be tasked with risk oversight across GMO’s investment and trading activities and supporting its quantitative research efforts.

Further, George Sakoulis, formerly a senior member of the GMO Emerging Markets Equity team, will rejoin GMO as its head of investment teams in August.

Sakoulis replaces Andy Martin, who will become the head of Investment Product Strategy.

Earlier, Sakoulis was QMA’s managing director and head of global multi-asset solutions.

Additionally, GMO appointed Carolyn Haley as the head of Operations, Finance, and Fund Treasury and Tax.

Existing COO Jean-Pierre Mittaz will now serve as a senior adviser.

At the same time, Hylton Socher recently joined GMO in the role of chief technology officer.

GMO CEO Scott Hayward said: “GMO has a deep history of benefitting our clients by pursuing contrarian strategies and taking advantage of significant market uncertainties.

“With George and Roy joining Ben and Andy in investment leadership, we are adding complementary expertise to our already strong team, and the acquisition of Usonian brings another differentiated alpha source to our clients.”