Airports group BAA yesterday posted a mixed performance for January as new services to India offset a sharp decline in trans-Atlantic travel.

BAA said passenger numbers rose 1.9 per cent after 10.1 million people passed through its seven UK sites -including Heathrow, Gatwick and Stansted - last month.

The group blamed the 3.4 per cent year-on-year fall in numbers travelling to the United States on higher fuel costs for operators and a softening economy which has seen fewer business people make the trip.

However, long-haul trips excluding the US were up 6.8 per cent after Virgin and BA began flying more services to India, including Mumbai.

The figures were announced a day after it emerged that Spanish infrastructure company Ferrovial was looking at a possible bid for BAA.

Shares jumped 15 per cent on Wednesday and were ahead another four per cent yesterday - even though BAA said results for January were mixed across its different sites and warned overall that conditions remained "subdued".

Heathrow Airport saw a 0.6 per cent reduction in footfall through its terminals, but Gatwick was up 2.1 per cent and Stansted ahead 6.9 per cent on a year earlier.

The monthly figures also revealed that Southampton saw passenger growth of 9.4 per cent, while Glasgow and Edinburgh rose 4.3 per cent and 3.6 per cent respectively.

And a surge in North Sea oil activity helped the number of passengers flying from Aberdeen airport soar 15.9 per cent.

Across the seven airports there was a 17.7 per cent drop in passengers on European charter flights, which matched a switch by operators to low-cost scheduled services.

The amount of cargo moved through the airports also increased by 2.6 per cent, the biggest rise since April, with 140,586 tonnes moved last month.

BAA plans to vigorously defend itself against any takeover bid by Ferrovial, sources said yesterday.

They added BAA will argue that its long-term growth strategy offers returns to shareholders that Ferrovial would not be able to match.

Opposition from bondholders to a change of ownership, BAA's £5 billion of debt and £6 billion to £7 billion in capital expenditure planned over the next ten years were said to be additional obstacles to a potential bid.

Morgan Stanley analysts said there were no legal hurdles to a possible takeover, but added the Government could demand certain guarantees from Ferrovial.

Meanwhile, Birmingham International Airport said it's year got off to a flying start with 564,702 people using the UK's fifth largest airport in January. This was 5.9 per cent up on the same month last year and the busiest January on record for BIA.

Scheduled traffic overall was up by 8.5 per cent during the month as more people took advantage of the growing range destinations available from Birmingham.