Tokyo: Japanese companies are slowing down their capital investment in the face of a stronger yen, rising material costs and concerns about the US economy. They plan to increase spending in plant and equipment by 3.7 per cent in the year to March 2009, representing the sixth straight year-on-year gain but the smallest rise in five years, the leading business daily Nikkei said on Sunday, citing a survey of 1,523 firms, mostly big companies.