Bloomberg is planning a sustained investment in its technology and news operations, arguing that it can gain market share even as sweeping changes in financial markets pose the biggest threat to sales of its data terminals in its 27-year history.

Peter Grauer, chairman of the company controlled by New York mayor Michael Bloomberg, told the Financial Times that it had seen a fall of just over 2.5 per cent in terminal numbers since they peaked in November, implying about 7,500 net cancellations from a subscriber base of about 300,000.

The private company rarely discloses sales details, but figures displayed on screens around its New York offices show that net monthly installations of terminals are running about 13 per cent behind last year's rate and Mr Grauer said he expected further falls.