News of the MPs' findings was taken badly in the City, where shares in BAA fell 17p to 507p.
The report*, by the Commons Transport committee, said that a company owning Stansted and Gatwick might be keener to attract traffic from Heathrow than BAA, which owns all three.
The five-yearly review of BAA's charges will take place next year and an MMC investigation could be ordered at the same time if it was felt that BAA, led by Sir John Egan, had taken action against the public interest.
But a BAA spokesman dismissed the report, saying the issue had been discussed often in the past without results. "Whenever airports in the UK have been looked at, it has been decided that the nation is better served by treating the three South-east airports as one airport system." The report also suggests that proposals to use Redhill and Northolt airports as extra capacity for nearby Gatwick and Heathrow should be actively considered. Northolt is used by business aircraft and the military, which owns it. A proposal to expand Redhill was rejected by a public inquiry last year.
The MPs also favour re-examining the long-standing proposal for an airport in the Thames Estuary. But there are doubts over the ability of the private sector to fund such a massive scheme which would involve the creation of a 3,500 acre island in the estuary. Like all previous such inquiries, the report criticises the planning process for large schemes such as airports. The MPs suggest that many of the technical issues raised at public inquiries which are "adversarial" should be dealt with at an earlier stage.
The planning inquiry into Terminal 5 at Heathrow is entering its second year and is not expected to be completed until mid-1997.
The MPs warn that they expect demand for air travel to continue well into the next century: "Estimates vary but passenger demand may well double over the next 10 or 15 years," they say.
With no prospect of any new runway being built in the near future, the committee recommends that ways of increasing capacity at Heathrow should be re-examined.
One suggestion is to allow take off and landings from both runways simultaneously, rather than alternating during the day, a proposal that will meet with widespread opposition from local residents.
* House of Commons Transport Committee, UK Airport Capacity, HMSO, pounds 11 50.Reuse content