London's top stocks have turned lower as investors take a breather following recent gains.British Airways has generated most headlines this morning. The embattled airline is drawing up contingency plans to cope if the planned 12-day strike by cabin crew goes ahead. An injunction is one option, but BA is said to be reworking schedules to minimise the damage.Banks are lower as the distance between the government and the industry over bonuses seems to get no nearer. Barclays and HSBC are the worst performers today.Costa Coffee owner Whitbread has offered to buy Eastern European coffee shop operator CoffeeHeaven for about £36m. The recommended offer of 24 pence in cash represents a premium of around 25%.Serco is confident enough about prospects to repeat forecasts for 2009 ahead of meetings with analysts prior to its financial year end on 31 December. The outsourcing group predicts double-digit revenue growth this year and a 30 basis point increase in adjusted pre-tax profit margin, excluding SI International which should increase growth by some 10%.National Express has received 90.47% acceptances for its £360m rights issue, the bus and trains operator confirmed Tuesday. Shareholders owning more than 323m shares subscribed for the fully underwritten 7 for 3 cash call at 105p a share.Bus and train group Go-Ahead expects interim profits from its rail business to halve though its bus business is doing better. Rail profits are expected to slide as growth in passenger numbers across its three franchises will not be sufficient to offset the reductions in net franchise subsidies from the government. Lloyd List publisher and exhibitions group Informa is still on track to hit forecasts this year. In a very brief statement, the group, which ended its interested in buying German publisher Springer earlier this month, it continues to trade in line with management expectations.A return to sales growth in the UK & Ireland helped carpets and floor coverings group Carpetright increase pre-tax profit by 16% and double the dividend. Profit before tax for the 26 weeks ended 31 October grew to £11m from £9.5m a year ago, which includes a £2.9m loss on the exit from Poland. Revenue rose 9% to £258m.Credit lender International Personal Finance (IPF) anticipates that full year results will slightly exceed expectations.