US billionaire Samuel Heyman, the London Stock Exchange's second largest shareholder, has increased his stake to over 10% less than 48 hours before the first deadline by which Nasdaq must secure the additional LSE shares it requires to succeed in its £2.9bn (€4.3bn) takeover bid.

Heyman Investment Associates, a hedge fund run by the billionaire, yesterday bought 162,000 shares at 1,283p, a 3% premium to the 1,243p a share takeover bid tabled by the US exchange.