The company is understood to have told investors it could pursue this strategy if a potential review by the Competition Commission calls for deregulation of the airport group. Analysts say such a move could add at least 100p to the value of the company’s share price. This will put pressure on Ferrovial, the Spanish construction group, that has tabled a hostile bid of 810p a share, valuing BAA at £8.75 billion.

Ferrovial is due to come back this week with an increased offer. After initial hesitation BAA investors have now welcomed an announcement by the Office of Fair Trading that it was considering a formal review of BAA’s position.

Michael Taylor, head of UK equities at Threadneedle, said: “The assumption of the market that the OFT review is bad news is misplaced. The regulatory situation at BAA hasn’t changed in 20 years — a review is long overdue.

“There is significant value in the BAA portfolio. There might be more value if the parts traded separately under light regulation which could benefit both customers and shareholders.”

Under BAA’s current regulatory regime, profits from all costs and tariffs, from landing costs to tax-free shopping and car-parking, are all strictly regulated. A lighter regulatory regime would allow BAA to raise landing charges at Gatwick, which rank among the cheapest of the world’s airports.

BAA could also have the flexibility to raise more debt against its extensive property and retail assets.

JP Morgan analysts said: “We believe the potential for either deregulation or break-up of BAA needs to be considered as a genuine possibility.”

But they are less optimistic about whether it would release value for investors. “A break-up could also trigger change-of-control clauses that might lead to funds destined for airport investment being diverted into paying early-redemption penalties on bonds,” they said.

Separately, the trustees of the BAA pension fund have appointed Kroll, the accounting firm, to advise on negotiations with bidders.

Last week the trustees reached an agreement with Ferrovial that includes ranking the pension deficit alongside senior debt in the event of BAA running into financial difficulties.

Additional reporting by Mark Kleinman

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