According to US sources, Boeing is expected to sign a provisional order from Qatar Airways for a new freighter version of its 777X passenger plane on Monday at a ceremony in Washington that coincides with a visit by the Gulf state's reigning emir.

According to a major Newswire, the US planemaker is in early talks with the Gulf carrier for roughly 34 of the projected twin-engined freighters, in a contract that is provisionally valued at $14 billion at list prices.

Qatar Airways has stated publicly that it is interested in purchasing up to 50 planes, with the greater figure believed to include options for future purchases.Cramer's Investing Club: Boeing's messy quarter does not change our long view on the plane maker

The agreement, which could be subject to the freighter project's formal launch, is due to be inked during a White House ceremony at 12:30 p.m. local time (16:30 GMT), according to authorities.

Boeing did not respond to requests for comment.

Qatar Airways, which has refused to comment on the Boeing cargo talks, could not be reached right away.