The department cited the company for 11 "apparent" instances of moving oilfield-related items such as spare parts, coiled tubing strings and pump sets, and called it "an egregious case" since the Jereh Group did not voluntarily disclose the violations.

Representatives for the company could not be immediately reached for comment.

"The apparent violations involved the exportation or re-exportation, and attempted exportation or re-exportation of U.S.-origin goods ultimately intended for end-users in Iran by way of China," it said in a notice on its website.

"The Jereh Group also exported certain U.S.-origin items with knowledge or reason to know that the items were intended for production of, for commingling with, or for incorporation into goods made in China to be supplied, transshipped, or re-exported to end-users in Iran," the department added.

Washington has imposed sanctions on Iran over its nuclear and ballistic missiles programs as well as for its alleged human rights abuses.

(Reporting by Susan Heavey and David Alexander; Editing by Steve Orlofsky)