CKE Restaurants has helped Pirate Capital to a $26m (€19.4m) profit on its investment in the US burger bar chain in just over a year, by repurchasing its entire 6% share stake in the company, and extending the activist hedge fund's improvement on its poor performance last year.

CKE, which owns the Hardee's chain of burger bars, said it had bought Pirate's holding for $77m (€58m), the market price giving the hedge fund a 50% return on its investment.