UK-based visitor attraction operator Merlin Entertainments has acquired the London Aquarium from County Hall Entertainment for an undisclosed sum.

In addition to the sale price Merlin has negotiated a 35 year lease on the site – located on London’s South Bank, next door to Merlin’s iconic The London Eye attraction – with landlord, Japan-based Shirayama Shokusan.

A spokesperson for Merlin said that the company intends to invest £5m in developing the displays and the infrastructure of the aquarium. The attraction will also be rebranded and will become part of Merlin’s Sea Life chain of aquariums.

He said: “Our marine experts already have plans in place for an extensive development programme designed to increase the interactive elements of the attraction, and to reposition the London Aquarium as a fun learning experience for visitors of all ages.”

Glenn Earlam, managing director of Merlin Entertainments’ Midway brands, added: “It is a wonderful site – big enough to be awe inspiring, but also very accessible for visitors.

“There is no one better qualified than Merlin to operate marine attractions; and when we add the Sea Life ‘magic’ we believe it will once again quickly become a must see attraction for Londoners, as well as those visiting the capital.”

Merlin is currently the world’s second largest visitor attraction operator – measured in annual visits – behind US-based Disney. The company, which is owned by private equity group Blackstone, owns and operates 52 attractions and six hotels in 12 countries and recorded visitor numbers of 32 million in 2007.

In March, Merlin announced its plans to open a London Eye-style observation wheel in New Jersey, US.

The Pepsi Globe, which is due to open at the Garden State’s new Meadowlands Xanadu complex in November, will be the first observation wheel of its kind in the country.