WASHINGTON: More than 120 US lawmakers raised concerns on Thursday about a deal for Alphabet's Google unit to acquire defunct carrier Spirit Airlines' internal data for US$10 million to train artificial intelligence systems.

As part of Spirit's closure and asset liquidation, Google won an auction in August for data from spreadsheets and calendars, as well as marketing, productivity and operations data. Spirit Airlines halted operations in May.

A privacy ombudsman on Monday recommended that a US bankruptcy judge approve the deal at an Oct 14 hearing, after excluding passenger personal information from 97 million Spirit customers.

The lawmakers, led by Senator Elizabeth Warren and Representative Steven Horsford, said the sale would include 100 million emails, 500 million Microsoft Teams messages and other employee records.