Everything was fine after Adidas purchased US-based Reebok in 2006. But things has changed in few years. It's struggling to boost sales. Reebok even lost a contract to supply the US National Football League. This has lowered it's market shared. And now things seem promising for Adidas and Reebok.Speculations are being made on Adidas and it's series of profit warnings."Reebok is one of the few brands enjoying some success for Adidas lately," Jon Copestake, retail analyst at The Economist Intelligence Unit told the Reuters news agency.Adidas's share rose 6% in early trading after a report explained a group of investors was considering a bid for the company's Reebok brand. Hong Kong's Jynwel Capital and investment funds in Abu Dhabi were considering an offer worth $2.2bn (£1.36bn) according to The Wall Street Journal. The news provided investors a support for rationalizing Adidas' share purchase and initiated boost for the German company's flagging share price which was down about 40% this year."From the Adidas perspective, that would be a great price. Whether management would accept it is another matter as it would be an admission of defeat," Joerg Philipp Frey ,Warburg Research analyst said.Adidas carried on Reebok acquisition to challenge Nike on it's home The Reebok acquisition was designed to help Adidas challenge Nike and eventually influence it's status as German company's own brand.Many investors are targeting Reebok now. German media reported last month that hedge funds including Knight Vinke, Third Point and TCI were doing internal works to buy stakes in Adidas to force management to make sweeping change and it even included the sale of Reebok,At beginning of October , Adidas announced plans to return as much as 1.5bn euros (£1.2bn) to shareholders over the next three year.In May it said that it was considering offers for its Rockport shoe brand, which it acquired when it bought Reebok. But Adidas has not yet announced any notice about accepting offers regarding Reebok.