A project team set up by Singapore Airlines evaluated both aircraft and decided to go with the European plane, the two sources said.
The full-service carrier will get up to 20 A320s worth $1.83 billion at list prices. The planes will be sourced from leasing companies, rather than purchased direct from Airbus.
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A Singapore Airlines spokesman referred queries to the joint venture's office in India, while an Airbus spokesman in Singapore said: "We do not comment on commercial discussions with existing or potential customers."
The new airline is expected to begin operations in the second half of this year.