Transactions With Palestinian Authority Prohibited
"On April 12, 2006, the Department of the Treasury’s Office of Foreign Assets Control (OFAC) announced that it had determined that Hamas has a property interest in the transactions of the Palestinian Authority. Because Hamas previously has been designated a terrorist entity whose property and interests are blocked under OFAC sanctions programs, OFAC’s determination means that, unless authorized, U.S. persons are prohibited from engaging in any new transactions and activities with the Palestinian Authority and must conclude any ongoing contracts or programs with the Palestinian Authority by May 12, 2006."
Read more in this Pillsbury Winthrop article from Mondaq.