(Adds value of order and details on fleet)
By Tracy Rucinski and Eric M. Johnson
CHICAGO/SEATTLE, Oct 1 (Reuters) - United Airlines said on Monday it has ordered nine more Boeing Co 787 widebodies to modernize its fleet as it expands its domestic network with additional coast-to-coast seats between New York and Los Angeles and San Francisco.
The Boeing order, worth $2.53 billion according to list prices, brings the U.S. planemaker's total 787 orders for 2018 to 105 aircraft, already surpassing the 94 orders it received in all of 2017, a source familiar with the deal said.
Reuters reported in May that Airbus was lagging behind Boeing in an effort to place its A330neo at United, which sets the tone for fleet decisions worldwide, and win a high-profile endorsement of its slow-selling jet.
United's expanded transcontinental routes are part of the third largest U.S. air carrier's plans to increase its overall capacity by around 4.5 percent to 5 percent this year, a faster pace than other airlines in the industry.
Under the plan announced on Monday, United will add more than 700 daily seats and 125 premium seats on 27 daily flights between New York/Newark and Los Angeles and San Francisco, thanks to an extra daily flight and the use of more widebodies on those roundtrip routes.
For example, some of the coast-to-coast flights will be serviced by its new and larger 787-10 Dreamliner jets beginning early next year.
As for the 787-9 order, United said it expects to take delivery in 2020 of the new aircraft, which will be used to replace older widebody aircraft.
In a separate statement, Boeing said nearly half of all 787 customers have returned to place additional orders for Dreamliner models, which can fly farther and use 20 percent less fuel with 20 percent fewer emissions than older widebody aircraft.
United, which has also been in talks with Boeing's main rival Airbus to modernize its fleet, said it will have 40 Dreamliner aircraft and 24 on order by the end of this year.
Shares in Boeing rose 2.9 percent to $382.53 in U.S. trade on Monday. Airbus closed 0.72 percent lower on Paris' benchmark CAC-40 index. (Reporting by Tracy Rucinski in Chicago and Eric M. Johnson in Seattle; editing by Bill Berkrot and Tom Brown)