Heineken NV (ENXTAM:HEIA) is seeking to raise its stake in United Breweries (Holdings) Limited (BSE:507458) to gain full management control, sources with direct knowledge of the matter said. Heineken, the single largest shareholder in United Breweries with a 42.07% stake, plans to take that holding beyond 50% by buying shares from Vijay Mallya and his group firms, the sources said.