US business leaders have offered a bleak view of the American economy, lowering their growth forecast for this year and urging the Federal Reserve to be cautious about raising interest rates. The Washington-based Business Roundtable, which represents the chief executives of large companies, said on Wednesday that its members expected the US economy to grow by 2.1 per cent in 2016, down from a forecast of 2.2 per cent in the first quarter, according to the group’s latest survey. The US economy, the world’s largest, grew at an annual rate of just 0.8 per cent in the first quarter, according to official figures, but most economists expect this to accelerate in the coming months.