(Removes reference to Frasers becoming top shareholder in ASOS in headline and paragraph 1, clarifies the change is to overall exposure, not actual shareholding.)

March 23 (Reuters) - British sportswear and fashion firm Frasers Group has increased its economic exposure in ASOS to 29.26% from 28.42%, a filing showed on Monday, after it added potential voting rights through put options in the online retailer.

Under UK takeover rules, an investor is required to make a mandatory offer for a company once its stake reaches 30% of the voting rights.

British sportswear and fashion firm Frasers, owned by billionaire Mike Ashley, has substantial investments in multiple retailers, including Debenhams, AO World and Puma. It has previously used its shareholdings to push for strategic changes or encourage companies to sell its products or adopt its services.

Frasers and ASOS did not immediately respond to emailed requests for comment.

Online retailer ASOS, which forecast 2026 profits below estimates in November, has been working to revive its appeal amid rising competition from Chinese rivals and to turn around its business through cost cuts.

(Reporting by Raechel Thankam Job in Bengaluru; Editing by Devika Syamnath)