China's desire to upgrade its slowing economy through foreign acquisitions could put it on a collision course with Japanese companies, which are also aggressively shopping abroad to escape stagnation at home.

ChemChina's $43 billion purchase of Switzerland's GMO-seed maker Syngenta, set to revolutionise food technology in China, has pushed China's outbound dealmaking spree to $65 billion this year, a record for so early in the year.

Japanese firms have so far in 2016 announced $3.5 billion of transactions, including Asahi Group Holdings' bid for the Peroni and Grolsch beer brands. With Japanese companies collectively hoarding an estimated $3 trillion in cash, according to Sanford C. Bernstein estimates, outbound M&A is expected to accelerate.

Buyers from the two nations have already clashed over an Italian train company last year, and sources say they could soon be among the pack chasing a Thai bank.

Chinese buyers are normally state-linked, and their aims often involve Beijing's industrial policy objectives, so profitability is not always the top priority, while Japanese buying is led by private companies looking to expand abroad to offset deflation, flat growth and a shrinking population at home. The Japanese buyers usually go for assets in their own sector, and relative to the Chinese are more constrained by shareholders in what they are prepared to pay. While China was focusing on seizing energy and food resources, the two rarely clashed.