Interesting point about the BAA profit margin. However, the figure after interest, tax and dividends is around 8% I think. Their annual report shows £158m carried to reserves which goes toward funding the £11.9 billion investment programme, so it looks like there's a gap to be plugged somehow - more borrowing ?? And that's probably a big issue in any break up of the monopoly - who could afford to a) buy one of the airports and b) put in the investment required, without jacking up the charges still further - back to the old Retail vs Operations argument.