( CNN ) -- Venezuela continues to nationalize private businesses , with President Hugo Chavez announcing late Monday that the government will take over two U.S.-owned Owens-Illinois glass-manufacturing plants . Chavez also ordered an environmental investigation at the sites , the state-run Agencia Venezolana de Noticias reported . Owens-Illinois did not know what will happen next , a spokeswoman said Tuesday . `` We have n't received official word from the government yet , '' said spokeswoman Stephanie Johnston . Venezuelan military personnel were at the company 's plant in Los Guayos , Johnston told CNN . No Venezuelan authorities were on the scene at the company 's plant in Valera , Johnston said . `` Both plants continue to operate as usual , '' she said . Owens-Illinois Inc. says it is the world 's leading glass container maker with more than 22,000 employees in 21 countries . The $ 7.1 billion company has global headquarters in Perrysburg , Ohio . Chavez , who has nationalized other industries and land holdings during his 11-year tenure , said he soon will announce the takeover of other foreign companies that have been `` exploiting the country 's working class . '' U.S. officials said Tuesday they were monitoring developments . `` We 've seen the announcement and are following the situation closely , '' the State Department said . `` We would expect Venezuela to provide prompt , adequate and effective compensation for any expropriation of the investments of Owens-Illinois in accordance with international law . '' Chavez nationalized a local unit of U.S. food giant Cargill last year . He previously has appropriated privately owned oil , telecommunications , power , cement and steel companies . CNN 's Arthur Brice and Juan Carlos Lopez contributed to this report .
Glass - Illinois owns two glass - manufacturing plants in Venezuela . The company said it had not received official approval from Venezuela yet . Venezuelan officials were at one of the plants , a company spokeswoman said .