ITG agrees to be acquired by high speed trading firm Virtu for $30.30 a share.
Deal creates major force in market making and technology.
Virtu Financial has seen its buy-side clients increase as a result of the impending MiFID II regulation.
Founder of Virtu, who formerly served in the US Army, will join US government in January.
A slow up-take in electronic trading of OTC derivatives has hampered Virtu's ambitious market-making plans.