Register now for FREE unlimited access to Reuters.com RegisterA tourist shows his "Green Pass", a document showing proof of coronavirus disease (COVID-19) immunity, as he enters the Colosseum, in Rome, Italy, September 16, 2021. REUTERS/Yara NardiNov 3 (Reuters) - Booking Holdings Inc (BKNG.O) topped market expectations for quarterly profit and revenue on Wednesday, but said a COVID-19 resurgence in Europe had cast uncertainty over year-end demand. Its shares rose 3.7% in extended trading as gross travel bookings surged 77% from a year earlier to $23.7 billion. Trends were improving in Asia, where higher vaccination rates and easing travel curbs boosted domestic travel, it said. Register now for FREE unlimited access to Reuters.com RegisterReporting by Nathan Gomes and Sanjana Shivdas in Bengaluru; Editing by Aditya SoniOur Standards: The Thomson Reuters Trust Principles.