Sports Direct International founder Mike Ashley has bought a 3.14% stake in Adidas Group to follow the successful floatation of his UK discount sports group.

The personal stake is considered by analysts to be a financial investment rather than the start of a takeover bid for Adidas, which is thought to be worth more than US$8bn.

Sports Direct floated on 27 February, netting Ashley close to GBP929m (US$573.5m) from an initial public offering of shares on the London Stock Exchange.

According to filings sent to the German stock exchange, the Adidas stake is worth around EUR270m (GBP183m). Earlier this week, financial group AMVESCAP increased its holding in Adidas to 5.087%.

Adidas shares were up 4% to EUR40.80 following the news, and upgraded by investment groups including Merrill Lynch.

Ashley, the executive deputy chairman of Sports Direct, is also pursuing a GBP75m offer for online sports goods retailer M and M Direct, according to The Daily Telegraph.

Sports Direct was unavailable for comment.