Apax and Permira, the European buy-out firms, are conducting a beauty parade of bankers for an initial public offering of Inmarsat, the satellite operator, in either London or the New York.

The planned IPO, which comes after two previous, aborted attempts to float the business, comes as PanAmSat, the US satellite operator, has added a further seven underwriters to manage its proposed $1.12bn (€857m) initial public offering.