The three people familiar with the matter, who declined to be identified because they were not authorised to speak publicly, said on Thursday Hartwall could fetch around 500 million euros and that interest was likely to come mostly from private equity firms.
Two people said Nordic private equity houses Nordic Capital and EQT could be interested. Heineken declined to comment.
Heineken, which had sales of about 18 billion euros last year, said in February it was looking at options for Hartwall and that it might sell the business.
Heineken, the world's third-largest brewer and Europe's largest beer maker, acquired Hartwall in 2008 as part of its joint purchase of Scottish & Newcastle with Carlsberg.
The unit produces beer, soft drinks, cider, wine and spirits and has about 850 employees. Globally, Heineken employs more than 85,000 people.
