Ernst & Young
On its website, Ernst & Young lists that it has an affiliate office, Tadvin Co./Tadvin Management Consultants, in Iran (Company Website, "Members of EYG and Its Affiliates," 7/31/09).
April 2010: EY has ended its business relationships in Iran. (The New York Times. "Companies Feeling More Pressure to Cut Iran Ties," 4/24/10)