Airlines could soon start offering customized fares to travelers based on how regularly they fly, where they live and the kind of trip they are taking.

The world’s largest airlines have agreed to adopt a new standard for distributing airfare information that could significantly compromise the privacy of customers and allow carriers to charge travelers different prices for the same trip. Airlines, of course, already charge different fares based on when a ticket is purchased, whether a Saturday stay is included and so on, but they are now looking to go much further by seeking to differentiate among fliers based on personal characteristics.

The new standard, which was agreed to at a meeting of the International Air Transport Association in October, will allow airlines to ask customers searching for airfares through travel agents or Web sites to first provide their names, frequent flier numbers, contact details and other information before presenting them with prices. A few airlines are expected to test this approach this year, and it could be widely adopted in a few years, according to the trade group. A majority of the group’s 240 members, which include most American airlines though not Southwest, voted for the standard.

Industry officials say the standard, which they call “new distribution capability,” is simply a way for airlines to better tailor their services to the needs of their customers. For instance, an airline might offer a package that includes free checked baggage, an aisle seat and a 10 percent discount to frequent fliers. And customers would be able to compare competing bundles from different airlines. They also say customers will still have the option of shopping anonymously for basic fares if they choose not to provide any information about themselves.