Meat processor JBS has reportedly made a verbal buyout offer for Sara Lee and is expected to submit a written proposal in the next 24 hours, according to sources.

JBS made its offer on Monday evening, Reuters reported, citing two unnamed sources. Bloomberg reported that JBS had indicated that the offer would be around US$21 a share.

Private-equity firm Blackstone Group is reportedly involved in JBS' pursuit of Sara Lee, and in one scenario, Blackstone would acquire Sara Lee's beverage unit if the Brazilian meat company's bid succeeds.

A private-equity consortium led by Apollo Global Management with Bain Capital and TPG have also reportedly made a $20 a share bid for the manufacturer, while KKR has also been linked to a possible bid for Sara Lee.