New additions to its portfolio and strong performances from its Lego attractions have boosted revenues for Merlin Entertainments, though the operator says its attractions in the UK are suffering as a result of recent terror attacks in the country.

Reporting its latest earnings, in the first half of 2017, Merlin recorded increased revenues of £685m (US$891.7m, €756.3m) – up by 9.6 per cent - while earnings before interest, tax, depreciation and amortisation (EBITDA) were £144m (US$187.5m, €159m) – an increase of 2.4 per cent.

Visitor numbers for the first half of the year were also up, increasing 6.2 per cent, with 29.7 million visitors to Merlin attractions so far this year.

Merlin said it had strong revenue performance despite some “difficult markets” particularly softness in the UK theme park market and its Midway attractions in London, which it called “subdued”.

“The series of terror attacks in the UK immediately and significantly reduced domestic demand, and we remain cautious on international visitation over the key summer trading period given the lag between international bookings and visitation,” said the operator in a statement.

For Merlin’s Midway division, which includes attractions such as Shrek’s Adventure, Dungeons and Sea Life aquariums, operating profits fell from £91m (US$118.5m, €100.5m) to £89m (US$115.9m, €98.3m), though this figure also included the opening of new attractions.

Merlin’s Legoland parks have performed well, with revenue increasing 8 per cent to £267m (US$347.6m, €294.9m), and operating profits up 32.1 per cent to £85m (US$110.6m, €93.9m). Merlin attributed these increases to the launch of Legoland Japan, a strong Easter period and new accommodation at its parks in Billund and Florida.

"We continue to be excited by the long term underlying growth prospects in our market and have the strategy in place to exploit these,” said Merlin chief executive Nick Varney.

“We remain on track to meet our 2020 milestone targets, supported not only by the attractions and accommodation opened to date, but also by the progress we have made on the pipeline, in particular the ongoing development of new brands which will underpin the longer term roll out."