Siemens Nixdorf Information Systems Ltd and the UK end of American Express Co are to launch the first unattended selfservice airline ticket machines; the machines are a consequence of a regulation passed last October by the International Air Travel Association which previously banned the dispensing of airline tickets without an authorised attendant; machines are to be installed in the premises of large corporations with which American Express has a business account and while travellers will book seats in the normal way over the phone, the ticket can be dispensed at any time without the aid of couriers or an agent at the airport: tickets have magnetic stripes so that similar machines can automatically check the passenger in at the airport.