New Delhi, Dec. 12 -- In India, airlines levy a 'seat selection charge'-a fee that is rarely disclosed clearly at the time of booking a flight and usually revealed only after one picks the air-travel service, often on the basis of fares listed upfront.

Air fares vary by cabin class-such as economy, premium economy, business or first-with no distinction between window, aisle, middle, front-row, rear-row or extra-legroom seats within the same class. Airlines treat all seats in a class as identical for fare displays, yet present seat selection as a paid-for service.

What began as an extra charge for a few preferred seats has morphed into a system that places a price tag on most, leaving only a handful free of charge-usually at the back of ...