Abu Dhabi-based investment firm, The National Investor (TNI), has appointed a new chief executive officer to replace Orhan Osmansoy, who resigned after nine years at the helm, the company said in a statement on Sunday. The new chief, Yasser Geissah, joins TNI after working with commercial and investment banking firms in the United Arab Emirates, including Abu Dhabi Invest Co, National Bank of Abu Dhabi and CAPM Investment. The statement did not mention where Geissah was most recently working.