U.S. blacklists Chinese, South African companies over Iran oil trade

WASHINGTON (Reuters) - The United States on Wednesday named seven companies that it has blacklisted for trade in Iranian petrochemicals, three based in mainland China, three in Hong Kong and one in South Africa, the State Department said in a statement.U.S. Secretary of State Mike Pompeo had said on Tuesday the agency was targeting such entities but did not name them.His announcement appeared designed to signal that Washington would not ease its campaign of choking off Tehran's ability to export..