Travis Kalanick, the pugnacious co-founder of Uber, has severed his last ties with the ride-services company, resigning from the board and selling all his shares as he turns his focus to a new venture creating ¡°ghost kitchens¡± for food delivery services.

Kalanick, who helped found Uber in 2009 and once exerted nearly complete control, stepped down as chief executive in June 2017 under pressure from investors after a string of setbacks.

He will depart Uber¡¯s board of directors by the end of the year, the company said on Tuesday.