Marsh, who takes up the newly created role this month, has been promoted from her position of global marketing director for Madame Tussauds. Her replacement on the waxwork brand is currently being sought.
Marsh will oversee the brand positioning and global marketing for Merlin Entertainment's "midway brands".
These are primarily indoor attractions that consumers will spend between two and three hours visiting, and include Madame Tussauds, the London Eye and the Blackpool Eye, Sea Life aquariums, Legoland Discovery Centres and the London Dungeon.
The global marketing directors for each of these brands will now report directly to Marsh, who in turn will report to Glenn Earlam, the managing director of Merlin Entertainment’s midway division.
Earlam said: "This is a very important role given our dynamic growth and the need to both ensure consistent brand propositions worldwide, while constantly looking to increase ‘the magic’ we provide."
The midway division sits alongside Merlin Entertainment's two other operating groups – Legoland parks and resort theme parks. The latter includes Alton Towers, Chessington World of Adventures and Thorpe Park brands.
The midway segment is the company's highest growth area, with six to seven attractions within the division opening globally each year.Follow @loullamae_es