Iran said it has reached an agreement with Boeing for the supply of airliners, reopening the country's skies to new US aircraft for the first time in decades, reports Reuters.

Details of the agreement were left vague, but could involve flag carrier Iran Air acquiring more than 100 Boeing jets, both directly and from leasing companies.

"In coming days details of the deal with this company will be announced," Roads and Urban Development Minister Abbas Akhoundi said, according to the semi-official Mehr news agency.

The agreement is so far only a broad outline of what a formal deal would look like once Boeing has the necessary US government approvals to sell planes to Iran.

So far, Boeing has only been granted permission to present its products to Iran Air and a handful of other airlines as it tries to catch up with Airbus, which has won a provisional deal for 118 aircraft worth USD$27 billion.

"We have been engaged in discussions with Iranian airlines approved by the US government about potential purchases of Boeing commercial passenger planes and services," a Boeing spokesman said.

"We do not discuss details of ongoing conversations we are having with customers, and our standard practice is to let customers announce any agreements that are reached. Any agreements reached will be contingent on US government approval."