French technology company Atos named a new chief executive on Monday and warned that free cash flow would be slightly below its initial target for the year’s second half, sending its share price tumbling. The firm said Paul Saleh, currently chief financial officer, would become CEO – the fourth in less than two years as it has grappled with a series of profit warnings. Atos, deemed strategic by the French government for its high-tech assets, including supercomputers used by the