The Adani Group, led by billionaire Gautam Adani, sold 2.8% of its stake in Ambuja Cements for Rs 4,200 crore, prompting a 4% rise in the stock. The group now holds a 70.33% stake in the company. Ambuja recently acquired Penna Cement at an enterprise value of Rs 10,422 crore, boosting its market share in southern India.