The move is an important step in plans by Tata Sons and Singapore Airlines to set up a full-service airline to compete for business amid India's crowded low-cost market. The fleet of 20 planes would initially be sourced from leasing companies, rather than purchased direct from Airbus. That decision triggered a race for the lucrative mandate between aircraft leasing companies gathering in Dublin for annual industry meetings this week. Industry sources who asked not to be named said the deal, or a significant part of it, was expected to go to BOC Aviation, the aircraft leasing subsidiary of Bank of China. BOC Aviation and Airbus declined to comment. "At this moment all that we can confirm is that Tata-SIA will be taking 20 A320 Airbus aircraft on a lease basis," a spokesman for the airline said by email.