Cineworld Group, operator of 78 cinemas in the UK and Ireland, has lost its chief financial officer, Richard jones.In an update Britain's only listed cinema group said "Richard has been with the Company for over 15 years and having achieved all that he wanted to achieve with Cineworld, he now wishes to embark on fresh challenges."The first part of 2011 has been difficult for Cineworld because although some films have been popular, notably The King's Speech and Black Swan, the older audiences interested in such films tend not to buy as much popcorn and soft drinks, which is where cinemas tend to make money.The latest available figures show total revenues for the 19 weeks to 12 May were down by 8.9% year-on-year, with box offices revenues down 7.8% and retail revenues falling 9.9%.However the company is yet to release figures for the period covering the release of Pirates of the Caribbean 4 and Kung-Fu Panda 2.BS