Sumitomo Chemical has agreed to buy a $590 million stake in Australian farm chemicals maker Nufarm in a surprise deal that knocked out a rival bid from China's Sinochem. While the deal evoked a tepid response from Nufarm and Sumitomo shareholders, it is seen by some as helping stabilize the Australian company and setting a floor for its shares after a series of profit downgrades. The move would offer joint development and distribution opportunities for Sumitomo in agrochemicals, which the Japanese company sees as a global growth business. The deal, however, is a blow to Sinochem's growth ambitions. Nufarm rejected a bid from state-owned Sinochem that had been cut to $2.3 billion after the Chinese firm completed due diligence following six months of talks.