Boeing aims for first flight of 777X in late June -sources

SEATTLE/PARIS, May 29 (Reuters) - Boeing Co is looking to make the first test flight of its 777X twin-aisle jet as soon as late June, people familiar with the matter told Reuters on Wednesday, slightly later than the planemaker had planned, but still on track for putting the plane into airline service in 2020.Boeing hopes the new jet will extend its grip on the 'mini-jumbo' market, which it shares with rival Airbus SE's 365-seat A350-1000, and perhaps scoop up fresh orders following the demise o