The US Justice Department has given the green light to takeover bids launched by the New York Stock Exchange and rival Nasdaq, after clearing them of competition issues. It comes as Nasdaq's deal was slapped with a $50m (€42.9m) lawsuit from a UK software company.

The DoJ's ruling clears the New York Stock Exchange to pursue a $3.5bn reverse takeover of electronic rival Archipelago, and Nasdaq a $1.9bn takeover of electronic broker Instinet.