ATG Entertainment, the biggest theatre group in the West End, owns 10 London venues including the Lyceum Theatre on the Strand - Anastasia Yakovleva/iStockHollywood billionaire and power broker Ari Emanuel has struck a £4.5bn deal to buy some of the West End's leading theatres. Mari Group, an events company founded by Mr Emanuel, confirmed on Tuesday that it had agreed to acquire ATG Entertainment, the biggest theatre operator in London. Mr Emanuel, 65, is the chief executive of talent agency WME Group and one of the most influential businessmen in Hollywood. Previously known as the Ambassador Theatre Group, ATG was founded in 1994 by husband-and-wife team Sir Howard Panter and Dame Rosemary Squire. Mari struck the deal with Providence Equity Partners, which bought the theatre group for £350m in 2013.