An additional US£800m (€577m, £476m) is being pumped into Shanghai Disney Resort to accelerate expansion plans – while it is still being built.

Joint venture partners The Walt Disney Company and Shanghai Shendi Group agreed the increased investment at a time of huge growth in China’s tourism market.

“We’ve been very impressed with the growth of China’s economy, especially the rapid expansion of the middle class and the significant increase in travel and tourism,” said Robert Iger, chairman and chief executive officer of The Walt Disney Company.

Thomas Staggs, chairman of Walt Disney Parks and Resorts, said the investment would allow the creation of additional attractions and entertainment, as well as other offerings to increase capacity at the theme park, with the majority targeted to be completed by the time the theme park opens before December 2015.

“The expansion underscores the tremendous opportunity we see in Shanghai and demonstrates our long-term commitment to and confidence in China,” he said.

Details of the new attractions and entertainment were not given.

Disney cited PhoCusWright research which projects that the Chinese travel market will grow 34 percent between 2012 and 2015. It also cited figures from US consultancy McKinsey which state that the number of upper-middle class and affluent households in China is expected to grow 18 per cent annually between 2012 and 2022.

The increased investment brings the total amount the two owners plan to spend on the park to about US$5.5bn.

Financing of the additional investment will be proportionate to ownership – Shanghai Shendi Group holds 57 permcent of shares while Disney holds 43 per cent – and the companies do not expect third-party debt to be incurred to finance the expansion plans.