The Langley, Berkshire-based provider of business services to the travel industry plans to realise around £1.2bn through the issue of new shares.
It intends reducing the debts taken on by Blackstone, the American private-equity group that purchased Travelport in 2006 for about £2.6bn.
The performance of the Travelport listing will be keenly watched by other companies which are planning to list in the next few months.
Travelport has recently hired former chairman of Allied Irish Banks, Dermot Gleeson, as its non-executive chairman.
Travelport runs the Galileo booking system for industry players such as travel agents, airlines and hotels. It is managed by chief executive Jeff Clarke from New York.