(10 Sep 2013, 3:58 pm)eezypeazy wrote As Far As I Know

AFAIK, each NTL participant holds shares in accordance with their market share... a new operator cannot be barred from joining NTL because that would be anti-competitive... At the date of joining, the shareholding would be amended accordingly, revenue divvied up amongst the previous shareholders the day before... if any scheme members' share of the market changes, their share of the revenue changes. So, for example, a Metro extension to Washington would almost inevitably see the PTE's share increase and GNE's fall (excluding the effect of new market generation).

NTL is a limited company, but I'd guess that the 'shares' are nominal and can't be bought and sold. And I haven't added them up, but are there 100 shares by any chance?

It really is very, very simple!

(But I still think taxis would be a safer option!)

Yes, there are 100 from quickly adding them up.
So if the shares aren't purchased, what does the £1 refer to?

Edit: Misread - there are roughly 1000 shares