The site has nearly 300 employees.
Florette UK & Ireland managing director Doug Robertson said: "MyFresh is a successful business that complements our existing operations and will help us to grow in the convenience retail and foodservice markets, both of which are showing consistent levels of growth and allows us to meet consumers’ needs for healthy food options, whatever the channel."
Florette UK & Ireland is owned by French food cooperative Agrial, which also owns Florette subisdiaries in six other European countries.
The other MyFresh UK site, at Chicksands, Bedfordshire, will continue to be owned and run by William Jackson Food Group and will trade under the MyFresh name for the forseeable future, the group said in a statement.
It added: "The sale to Agrial is a fantastic opportunity for the Wigan site. The new owners are experts in fresh produce with a long history of investing in, and growing business in the sector; they are committed to the future of the business at the Wigan site."