India needs to increase the money it spends on improving roads and other infrastrastructure projects by four times - to about $100bn a year - if it is to have a chance of maintaining the pace of its recent economic expansion, according to one of India's leading business executives.

A M Naik, chairman of Larsen & Toubro, a Mumbai-based engineering and construction conglomerate, said: "There is no alternative to improving India's infrastructure if we want to keep the economy growing at 7-8 per cent a year and in particular help the expansion of manufacturing."