Britain's biggest supermarket Tesco has confirmed it is entering a joint venture with Indian conglomerate Tata Group in which it will invest 85m pounds.The retailer will form a 50:50 joint venture with Tata-owned Trent Hypermarket which operates the Star Bazaar retail business in India.On completion Trent Hypermarket will operate 12 stores which see a range of items from food and grocery to home and fashion.Stores are functioned under the Star Bazaar and Star Daily banners spread across the Southern and Western regions of India. At present Tesco operates in India with a service centre and franchise arrangement with Tata Group.As of 14:05 the share price had dropped 2.55% to 289.9p.