Tour operator Thomas Cook in financial trouble (AP)

People walk-by a branch of Thomas Cook travel agent in Borehamwood, north London, Tuesday, Nov. 22, 2011. Shares in tour company Thomas Cook lost two-thirds of their value after the company issued a profit warning Tuesday. (AP Photo/Sang Tan)AP - Fears rose over the survival of venerable British tour operator Thomas Cook after financial problems worsened Tuesday for the company that took more than 22 million people on holiday in the latest year.