The Competition Commission inquiry was launched after the Office of Fair Trading found that the firm's seven UK airports may "prevent or restrict" competition.
What share of air passengers does BAA have?
Its seven airports account for 60 per
cent of passengers across the UK, but this rises to 88 per cent in lowland Scotland and 90 per cent in the south-east of England.
What are the perceived benefits of greater airport competition?
Rival operators may cut landing charges to attract more airlines and routes and improve terminal facilities to lure more passengers.
So why is opinion split in Scotland over whether BAA should be forced to sell Edinburgh or Glasgow?
Several business groups argue the airports serve different areas rather than compete with each other.
Why is there concern about introducing controls at Aberdeen airport to offset its local monopoly?
There are fears that this could put other airports, such as Inverness, at a competitive advantage if they are free of such restrictions.
What happens next?
The Competition Commission is seeking responses to its "provisional findings" by 17 September. There will be a final decision by March.
Do the plans have to be approved by the government?
No. The commission is independent of government.
Who might be interested in buying any airports put up for sale?
The owners of other major UK airports, European airport operators, state-controlled sovereign wealth funds in the Gulf and pension funds.
Why does BAA no longer call itself the British Airports Authority?
Because that was the name of the state-run organisation which was privatised by the Conservatives 21 years ago.
The full article contains 287 words and appears in The Scotsman newspaper.
