Shares in travel group Thomas Cook fell back after it posted a rise in revenues in the nine months to June 30, but said it took a £12.6m hit due to the swine flu outbreak and added that it is unlikely to achieve its targets for 2010.Revenue for the nine month period climbed by 10.7% from the same period the previous year to £5.9bn, while losses from operations before exceptional items and swine flu reduced by 43.4% to £49.5m. The company estimates that the disruption caused by swine flu, which prompted the government to advise against travelling to Mexico, cost the company £12.6m.Thomas Cook said it is confident of meeting its expectations for the current financial year, but said continued economic weakness means a target to achieve £480m in operating profit in the 2010 financial year is 'not realistic.'While there has been a shift towards late bookings this summer, the firm said, load factors - a measure of how full planes are - have been in line with last year's levels at 96%.