Delivery of the Tupolev Tu-204 planes would violate US sanctions because the US company Pratt & Whitney helped develop their engines, Alexander Rubtsov, the director of Ilyushin Finance which has the contract to deliver the planes, told Reuters.
"There is such a problem," Rubtsov said by telephone. "We will offer planes with different engines."
Russia has sharply criticized the United States for hitting Tehran with unilateral restrictions in addition to the sanctions adopted by the UN Security Council, saying nations seeking to ensure Iran does not obtain nuclear weapons must act as one.
Moscow is struggling to balance trade ties with Tehran and warmer relations with the United States, which is eager for Kremlin support to rein in nuclear activities it says it believes are aimed at weapons development.
Iran has expressed anger over Moscow's backing of sanctions in the Security Council, where Russia holds veto power.
The PS-90A2 engines in the passenger planes were made by Russia's Perm Motors in conjunction with Pratt & Whitney, a unit of United Technologies Corp.
Rubstov said Ilyushin Finance, which is part-owned by state-controlled United Aviation Corporation, would propose planes with an earlier version of the engine, the PS-90A.
He did not say how much the contract was worth or when the US sanctions preventing the delivery had been adopted.
The United States has introduced increasingly tight trade restrictions against Iran and took steps on Monday to make it harder for Tehran to skirt the sanctions.
