Indian billionaire Adar Poonawalla is set to purchase a London mansion, Aberconway House, for £138 million (Rs 1,440 crore), marking the city's priciest home sale this year. The property, owned by Dominika Kulczyk, will become the second-most expensive residence ever sold in London. Poonawalla's Serum Life Sciences, a UK subsidiary of Serum Institute of India, will acquire it.