Boeing added 20 new orders for the 777 this week, but also lost signed orders for another four 777s.

The Chicago-based manufacturer posted a weekly order update on 6 May.

The Boeing document did not identify the source or sources who purchased the 20 777s, listing the buyer as "unidentified".

So far, Boeing has booked 134 new orders since 1 January. Customers also have pulled orders for 22 aircraft, so the net increase to Boeing's backlog is 112 aircraft.

Net orders so far this year include 70 737s, 27 777s and 15 787s.

Source: Air Transport Intelligence news