United Airlines (UA, Chicago O'Hare) has signed an agreement with Boeing (BOE, Chicago O'Hare) to convert 100 of its 161 existing B737 MAX order slots into B737 MAX 10s.

United's Senior Vice President (Finance & Procurement) and Treasurer, Gerry Laderman, said during a press conference that the airline expects to begin taking delivery of its first ten B737 MAX 10s in 2020. The aircraft will be reserved for the US domestic market and will not replace its transatlantic B757s or its B767-300(ER)s, he said.

Separately, he noted United's first B737-9 is due to arrive in April 2018.

In a statement issued during the 2017 Paris Air Show, the carrier also announced an order for four more B777-300(ER)s, bringing its total order backlog for the type to eighteen.