A 10 per cent increase in visitor numbers compared with the previous year helped to fuel the group's growth over the 12-month period amid what it called a difficult trading environment.

The attraction operator was also boosted by the opening of Madame Tussauds Hollywood, US; Sea Life Porto, Portugal and the relaunch of the London Aquarium during the year as the group continued its roll-out of Midway Attractions.

Merlin chief executive Nick Varney said: "During 2009, as well as delivering strong increases in both sales and profits we have reduced debt leverage, leaving the group better positioned than ever before.

"As we approach the start of our key trading period we have exciting new developments in place in all of our attractions, which will ensure we continue to deliver memorable experiences for our customers worldwide and keep us on track for another year of growth."