The Cosmen-CVC Capital Partners consortium bidding for National Express is looking for ways of making its offer more attractive after the train and bus operator rejected a conditional all-cash 450p takeover proposal last week.

Stagecoach, a rival transport group that had been in exclusive discussions with the Cosmen-led consortium about buying some of the assets of National Express, was on Tuesday locked in talks with the Spanish who already own 18.5 per cent of the company.