Nellson Nutraceutical, an Irwindale nutrition bar and powder maker, plans to acquire Le Groupe Multibar Inc., a Montreal-based manufacturer of nutritional and snack bars, Nellson announced Monday.

Scott Greenwood, Nellson’s chief executive, will retain his title in the combined entity. Jean Filion, Multibar’s president, will stay on as a member of the executive management team. The transaction is expected to close in approximately 30 to 60 days, the companies said.

The combined company will have four manufacturing facilities, as well as research and development centers, in the United States and Canada.

Nellson, a portfolio company of New York private equity firm Kohlberg & Co., and Multibar are both third-party manufacturers, making bars and powders for other companies.