TUI, the leading European tourism group, said Wednesday that its Swiss and Polish subsidiaries had cancelled flights with Cyprus' Helios Airways following the fatal crash of one of its planes in Greece. A spokesman for the Hanover-based German group said the move affected four flights scheduled in the autumn by TUI Switzerland, as well as twice-a-week flights by TUI Poland through the end of the peak travel season. TUI, based in Hanover, cited "strong demand for information by clients" for the cancellations. A Helios Boeing 737 plane crashed Sunday into a hillside near Athens, killing all 121 passengers and crew. The spokesman's remarks confirmed information to be reported in Thursday's edition of the German business daily Handelsblatt. The customers affected will fly on alternative airlines, he added. The spokesman said he did not know whether the only other TUI unit using Helios flights, TUI Scandinavia, would continue to do so. In Berne, a spokesman for TUI Switzerland, Roland Smith, said the cancellations were made because of uncertainties surrounding the investigation of the accident and for the well being of the company's clients.