PARIS, June 20 (Reuters) - United Airlines has converted an order for 100 Boeing 737 MAX jets into one for the U.S. planemaker's new 737 MAX 10 model, the companies said at the Paris Airshow on Tuesday.
United Airlines, which will become the largest single 737 MAX 10 customer in the world, also announced an order for four additional Boeing 777-300ER aircraft.
Asked by reporters why the latest deal was a conversion of a previous order, rather than a new one, United Airlines executive Gerry Laderman told Reuters: "We have a very healthy order book ... and it is very customary for us to place an order to have a certain timeline/time slots, and closer to the time we pick which model we want."
Laderman added that United Airlines already had a large MAX order, so there was no need for an incremental one. (Reporting by Giulia Segreti; Editing by Sudip Kar-Gupta and Mark Potter)