Ethiopian Air Buys Up to 20 Behemoth 777X Jets, Boosting Boeing

Ethiopian Airlines agreed to buy as many as 20 of Boeing Co.’s massive 777X aircraft, providing the coming jet with an important endorsement from one of Africa’s premier airlines.

Mesfin Tasew, chief executive officer of Ethiopian Airlines Group, unveiled the latest deal Tuesday in Addis Ababa. The airline placed a firm order for eight 777-9, along with options for another 12 of the hulking jetliners, designed to seat more than 400 travelers.

The deal — with a value of about $11 billion, Tasew said — provides some sales momentum for Boeing as it works to complete certification of ...