U.S. Eyes Sanctions Against Global Network It Believes Is Shipping Iranian Oil

WASHINGTON—The U.S. is considering sanctions that would target a United Arab Emirates-based businessman and a network of companies suspected of helping export Iran’s oil, part of a broader effort to escalate diplomatic pressure on Tehran as U.S. officials push to reach a deal on Iran’s nuclear program.

The firms and individuals under scrutiny have been using ship-to-ship transfers of oil in waters that lie between Iraq and Iran and then forging documents to hide the origin of the cargo, according to corporate documents reviewed by The Wall Street Journal, shipping data and people familiar with the matter. By passing off the blended oil as Iraqi, those involved can avoid Western sanctions targeting Iranian oil.