The company released a statement on September 1 to say it would keep an interest in the storage and sorting of potatoes but wanted to exit processing to focus on its core businesses.
"This way, the potato processing will get a number of engaged, Swedish growers for owners - which feels very positive," said Lantmännen chairman Thomas Bodén.
The deal, signed for an undisclosed fee, allows a group of growers to gain control of a business that processes potatoes under the Solanum and Alströmer brands.
In July, Lantmännen said it had swung into the red during the first half of 2009 despite "good results" from its food division.
#Potatolovers, Keep calm and recommend #potatoes! #Potatobusiness http://t.co/89RPHelmL3