The $6.1-billion deal still requires approval from the Chinese Ministry of Commerce under the country's anti-monopoly law, the final regulatory hurdle facing the companies.
The agreement received approval under the Investment Canada Act in July.
The companies said they have extended the outside date for closing the deal by one month to Nov. 15.
Glencore has agreed to increase Viterra's projected capital expenditures in Canada by more than $100 million over five years and has said it will contribute to "grain industry initiatives" in Manitoba.
It has also committed to maintaining Viterra's Regina head office and said it will make the location the headquarters for its North American agricultural operations.
Glencore also plans to invest $8 million in Viterra's projected expenses in research and development and plans to work with the Saskatchewan government to establish a Global Institute for Food Security in the province.
Viterra has operations across Canada, the United States, Australia, New Zealand and China.