Expedia is offering to find airline, rental car and hotel rooms for other Net travel sites, the online travel agency said Monday. Expedia will provide its own booking tools under a private label to other agencies. American Airlines has signed up as the first customer for its Web unit, AA.com, said Suzi Levine, Expedia spokeswoman. Based in the Seattle area, Expedia will handle customer services issues. Worldwide Travel Exchange is part of Expedia's push to grow its business-to-business side of its business.