Travelport, the airline and hotel reservations group, is planning a £1.2 billion London stock market listing to pay debts taken on by its owner, Blackstone, the cash-strapped U.S. equity group with assets that include the Hilton Group.

The group runs the Galileo booking system for travel agents, airlines and hotels. In its most recent quarter, the company reported earnings of $93 million (£57 milion) on sales of $570 million. The floatation is expected to value the company at £1.8bn.

The flotation is being handled by UBS, Goldman Sachs, Barclays Capital, Citigroup, Credit Suisse and Deutsche Bank.

If successful, the flotation would be the biggest stock market listing since Fresnillo, the Mexican-based silver miner, floated in spring 2008. It will be keenly watched by financial markets as a barometer of the confidence of the IPO market. 

A host of other privately-owned companies, including Ocado, the online grocery retailer, Pets at Home, fashion retailer New Look and Merlin Entertainments, the owner of Madame Tussauds and Warwick Castle, may bring forward their flotation plans if Travelport’s listing proves successful.

Travelport had planned to float in 2008 but pulled its plans when the markets nosedived.

Blackstone bought Travelport for $4.3bn (£2.6bn) from American company Cedant in 2006, before merging the group with its rival Worldspan.

Other investors include Technology Crossover Ventures, One Equity Partners and the company’s management.