The United States has imposed sanctions on a Turkish investment bank and two subsidiaries, accusing them of helping Iran move oil revenue and providing access to the international financial system as Washington intensifies its campaign to squeeze Tehran. The US Treasury Department on September 4 designated Istanbul-based Golden Global Yatirim Bankasi Anonim Sirketi, along with Golden Global Portfoy Yonetimi and Golden Global Varlik Kiralama, under its Iran sanctions authorities. The three entities were added to the Treasury's Specially Designated…