3i Group has supported the acquisition of drivetrain testing specialist Straesser by the GP's portfolio company Atesteo.
GP is deploying capital from its Gradiente II fund, which held a first close in November 2017
JV will be based in London and led by 21 Partners' founder and managing partner Alessandro Benetton
Vendors include Sunstone Capital, Ysios Capital Partners and Forbion Capital Partners
New investment will be used to scale up operations in Germany and the US