Adidas Chief Executive Kasper Rorsted plans to complete the sale by March 2021, the magazine said, without citing where it obtained the information.
Manager magazin said U.S. apparel maker VF Corp and China's Anta Sports were among the interested parties, without citing sources.
Adidas declined to comment.
VF Corp did not immediately respond to a request for comment, while Anta Sports could not be immediately reached for comment outside office hours in China.
Shares in Adidas jumped as much as 3.5% on the report, reflecting hopes for a sale following repeated calls to dispose of Reebok from investors who criticised a lack of progress in turning around the business.
The German company bought Boston-based Reebok for $3.8 billion in 2005 under Rorsted's predecessor Herbert Hainer, aiming to take on U.S. arch rival Nike on its home turf.
Last year, however, Adidas wrote down Reebok's book value by nearly half compared with 2018, to 842 million euros ($995 million). The unit's sales fell 44% in the second quarter of 2020 to 228 million euros, leading to its parent taking impairment charges in the period.
Rorsted had flagged in March that Reebok's role within the group would be decided as part of Adidas' new strategy, to be unveiled next year.
(Reporting by Christoph Steitz and Alexander Huebner; Editing by Thomas Seythal, Keith Weir and Pravin Char)