Global private equity giant Blackstone Group has emerged as a backer of Tungsten Corporation, the listed financial services-focused investment vehicle run by City of London financier Edi Truell.

Tungsten floated on London's junior Alternative Investment Market last October and raised £160 million, which it has used to buy a business-to-business invoicing network called OB10 as well as the UK arm of First International Bank of Israel, which will be used to pay those invoices.