A former executive of German pharmaceutical and chemical firm Bayer AG agreed to a four-month prison term as part of a plea agreement in a probe into price fixing in the rubber chemicals market, US officials said Monday. The Justice Department said Wolfgang Koch, a German national, also agreed to pay a 50,000-dollar (63,000-euro) criminal fine and to assist the US government in its ongoing rubber chemicals investigation. US officials said Koch was product manager of rubber chemicals at Bayer during the time of the alleged conspiracy. "Individuals who participate in illegal price-fixing conspiracies affecting products sold in the US will be prosecuted regardless of nationality," said R. Hewitt Pate, head of the Justice Department's antitrust division. "These conspiracies harm millions of American consumers." Last year, Bayer AG agreed to pay a 66-million-dollar fine to settle charges it participated in the price fixing with unnamed chemical producers. Rubber chemicals improve elasticity and strength of rubber products such as tires, outdoor furniture, hoses, belts and footwear.