SOUTHAMPTON Airport operator BAA will today get the first official indication of whether it will be forced to break up its UK airport empire.

The Competition Commission (CC) will publish a document outlining its "emerging thinking" in its inquiry into BAA and UK airports.

Although only a progress report, the commission could give a sign that it is thinking of ordering a break up of BAA airports which include not only Heathrow, but also Stansted and Gatwick, as well as Glasgow, Edinburgh and Aberdeen.

It is thought unlikely BAA will be ordered to sell Southampton, with speculation suggesting the Spanish-owned firm is looking to sell Gatwick in West Sussex and there have been reports that there have been talks with potential buyers for Stansted as well.

There have been calls for this ''monopoly'' to end, with opponents of BAA pointing to continuing travel chaos at Heathrow, which culminated in the shambolic T5 opening.

When the inquiry chairman Christopher Clarke listed the issues the commission would be looking at, he said: "We are well aware of the concerns expressed in the media and elsewhere over the operations of BAA's airports.

"These include delays experienced by passengers going through security or immigration...and other aspects....such as overcrowding, signage and cleanliness.

"We are looking at how common ownership could affect BAA's incentives both to invest in and develop its airports, and operate them."

In referring BAA to the CC, the Office of Fair Trading said there was evidence of "poor customer satisfaction" and that in the south east of England, BAA's airports handled 90 per cent of passenger trips "and these airports could under separate ownership compete to attract air passengers".