AFAIK, it's not a question of "buying" NTL shares. NTL is simply a way of dividing up the revenue between scheme participants based on market share (however that is measured). In all probability, A1 Buses will help to grow the total market, so there'll be more NTL revenue to go round, but there's a risk - say, for example, everyone on all your buses every morning buys from you a T&W Day Rover ticket, and shows it on their return. You've got the revenue from the morning, and you record the ticket use in the afternoon. BUT let's say that they all use each Day Rover on two other operators' buses, and they record the use of the ticket. You therefore owe the other operators a share of your NTL takings for the ticket use. So, you've banked the cash, but you also have a liability to NTL. Equally, when you accept a Day Rover sold elsewhere, you're clocking up an NTL credit.

My understanding of such schemes is that, at the end of a given accounting period, there will be some sort of declaration of takings and usage and an appropriate division of the proceeds. In some periods you might gain, or you might find you owe money to the scheme.

I'm guessing, but I'd bet that the NTL 'assets' and 'liabilities' relate entirely to cash waiting to be reconciled.