Polar Capital announced that chief executive Mark Kary will step down as chief executive of the asset manager with immediate effect to pursue alternative career interests.Tim Woolley, currently executive director, and one of the two original founders of the business will take over as chief executive. Kary will remain with the company until the end of the year to assist in an orderly transfer of his responsibilities. The group said Kary's departure follows a period of strong recovery in Polar Capital's business and is entirely amicable.