The German company said it had “started evaluating strategic alternatives” for Reebok which could include a sale as part of a new five-year strategy to be defined in March.
Adidas bought Reebok in the United States in 2006 for $ 3.8 billion (£ 2.8 billion) in an attempt to strengthen its home market presence from rival Nike.
The acquisition did not go as planned and Adidas chief executive Kasper Rorsted came under pressure to sell the brand.
Attempts to turn the tide have included signing up Game Of Thrones actor Nathalie Emmanuel, models Gal Gadot and Gigi Hadid, and singers Cardi B and Ariana Grande as brand ambassadors.
The business, which lost 150 million euros (134 million pounds sterling) in 2016, returned to profitability in 2018.
But it suffered a setback when sales were hit harder earlier this year by the COVID-19 pandemic than those of the Adidas group at large.
A statement on Monday confirmed a report in October that Reebok was to be sold.
Shares rose about 2%.
It was also reported in October that the Adidas boss was now prepared to accept a sale value of less than € 2 billion (£ 1.8 billion) he allegedly attached to the brand before the pandemic.
Reebok – a company with an illustrious history – can trace its origins to Foster’s Running Pumps, a British company founded in Bolton in 1895.
His origins can still be seen on the Union flag on his shoes.