ATHENS (Reuters) - Europe's largest holiday operator TUI Group plans to expand in Greece, it said on Friday, signalling confidence in the tourism-dependent country's efforts to emerge from a long economic crisis.Tourism is a pillar of Greece's economy, accounting for about a fifth of annual output of 180 billion euros and a fifth of jobs. Visitors, led by Britons and Germans, have increased by about 50 percent since the crisis began eight years ago."We have been here for 40 years and we will be here for another 40," TUI CEO Friedrich Joussen told reporters after meeting Prime Minister Alexis Tsipras. "I see a greater future for tourism in Greece."As well as expanding its asset base of 32 hotels and adding cruise port destinations, TUI was ready to join in efforts to extend the tourist season beyond the summer, Joussen said. "It is a great opportunity for us. We will grow our business," in the hotel and cruise port sector, Joussen said."Infrastructure is the fuel for the overall prosperity of the economy and society ... the investments here will definitely pay off." Greece signed up to its first international bailout in 2010. Its third rescue package expires next year and the country needs foreign investment to help drive the economic recovery and job creation it will need to ensure it become financially self-sufficient.Its tourism revenues fell 7 percent last year as a financial squeeze across Europe slashed holiday prices and average stays, but arrivals including cruise passengers rose to 28 million. TUI said that this year its Greece-bound customer base rose 9 percent to 2.5 million.Greek authorities have spoken for years about extending the tourist season, but the country would have to implement reforms to attract tourists, including TUI customers. "We need some sort of a masterplan for certain destinations," Joussen said."....If you want to open (the island of) Crete for a couple more months, we can open Crete ...But if shops are closed and restaurants are closed because the season is over, then the customer might come one time, but not a second one." Currently, many Greek tourism businesses work only during the high summer season. (Reporting by Renee Maltezou; editing by John Stonestreet)