Abu Dhabi’s International Holding Company (IHC) on January 30 said it will invest $400 million in Adani Enterprises’ ongoing Rs 20,000-crore follow-on public offer (FPO) via its subsidiary Green Transmission Investment Holding RSC Limited.IHC, one of Abu Dhabi’s most valuable listed companies, was an investor in Adani Enterprises’ share offering’s anchor book as well.