The first half of the year has been a mixed bag for Merlin, with the operator reporting revenue increases of £24m (US$31.4m, €27m) for the first half of the year, but a decline in operating profits, which were down £10m (US$13m, €11.3m).

For the 26 weeks ended 30 June, revenue was £709m (US$927m, €798m), up from £685m (US$895.7m, €771m) for the same period in 2017, representing a 3.5 per cent rise.

Operating profits took a significant hit, down to £63m (US$82.4m, €71m) – a 14.3 per cent decline. Earnings before interest, taxes, depreciation, and amortisation (EBITDA) also dropped slightly, down 1.3 per cent to £143m (US$187m, €161m), compared to £144m (US$188.3m, €162m) for the period last year.

According to Merlin, the decline in profit was due primarily to adverse foreign exchange movements and a higher depreciation charge due to new business development.

"In the existing estate we have been pleased with trading in the resort theme parks operating group," said Merlin CEO Nick Varney.

"We've had strong customer reception to our product investments and we continue to see the anticipated recovery at Alton Towers. The business has also undoubtedly benefited from the recent warm weather in Northern Europe which due to the natural balance of our portfolio has conversely had an adverse impact on our indoor Midway attractions.

"Having so far traded in line with expectations we are now entering our peak season, where we generate the majority of our annual profit. With many exciting new initiatives and launches to come in the future, we remain confident in our long term prospects."

Merlin has a number of developments currently in progress at its visitor attractions worldwide, including new Midway attractions including Justice League at Madame Tussauds Orlando and Sydney; the Lego City: Deep City Adventure at Legoland California; the Wickerman wooden coaster at Alton Towers; and the Peppa Pig additions at both Heide Park and Gardaland.

Merlin is also continuing its initiative to turn its theme parks into destination resorts, with a total of 644 new rooms opening in 2018. These include the 252-bedroom hotel at Legoland Japan, the 250-bedroom Legoland California Castle Hotel, and the 142 bedroom Pirate Island Hotel at Legoland Deutschland.

Further attractions opening this year for the operator include Sea Life at Legoland Japan, the Legoland Discovery Centre and Bear Grylls Adventure in Birmingham, Peppa Pig World of Play in Shanghai and Little Big City in Beijing. Legoland New York is also making progress, and is expected to open in 2020.