The company entered into a joint venture with French retail foods giant Danone for the sale of yogurt and desserts, in 1996. It continued to develop new products for the local market, such as phytosterol-enriched milk in 2000, juices for infants, in 2001, and linoleic acid-enriched milk, in 2003. It also became more active in public service efforts, such as in the establishment of an environmental impact bureau in 2002 and of a fund-raising effort for the non-profit Favaloro Foundation, in 2003.

La Serenísima, which processed over 4.8 million tons of milk annually, was recognized as one of the world's most prestigious names in its sector by Global Marketing Research, in 2004. Through Danone, it introduced Activia to the Argentine market in 2005, and in June 2009, Danone reportedly entered into talks to acquire 100% of Mastellone Hermanos S.A., La Serenísima's parent company, though the latter's US$260 million debt and reported opposition to the sale on the part of former President Néstor Kirchner has since delayed the deal.