(Changes "two U.S. licences" to "a U.S. licence" in para 3)

PARIS, Sept 21 (Reuters) - The United States has started issuing licences unblocking the sale of Western passenger jets to Iran, aviation sources said. The U.S. Treasury has issued licences allowing the export of some European Airbus AIR.PA jets to Iran and is expected to start approving sales of Boeing BA.N jets within days, the sources said.

A spokesman for Airbus confirmed it had received a U.S. licence covering a total of 17 aircraft slated for early delivery. Although based in Europe, Airbus needs U.S. approval because of the high number of U.S. parts in its jets.

Both planemakers have agreed to sell or lease more than 100 aircraft each to flag carrier IranAir as Iran rebuilds its aviation sector following last year's agreement between Tehran and major powers over the lifting of nuclear-related sanctions.

(Reporting by Tim Hepher; Editing by Ingrid Melander) ((tim.hepher@thomsonreuters.com; +33 1 49 49 54 52; Reuters Messaging: tim.hepher.thomsonreuters@reuters.net))

Keywords: IRAN AVIATION/