The Northern Ireland Audit Office (NIAO) has published its review of the Northern Ireland Tourist Board's (NITB) Signature Projects.

Among the developments examined as part of the NIAO study is the Titanic Signature Building in Belfast and the new Giant's Causeway Visitor Centre in County Antrim.

The total cost of the Signature Projects, which also include the Walled City of Derry, will be £159m when complete, of which £71m will have been funded through NITB.

According to the NIAO, the Titanic Signature Building - due for completion in March 2012 - will need 290,000 visitors each year to break even and may face an uncertain future if predicted tourist numbers are not realised.

The NIAO also raised concerns about the appeal of the attraction, with the economic downturn leaving many parts of the Titanic Quarter undeveloped.

Meanwhile, the Giant's Causeway Visitor Centre - due for completion in July 2012 - will require "challenging" operating revenues of £1.6m a year in order to cover its costs.

The NIAO said: "There is a risk that their impact may fall short of the anticipated 'step change' in tourism in Northern Ireland.

"In particular, a number of issues could affect the value for money, impact and sustainability of the two largest single elements of the Signature Projects - the Titanic Signature Building and the Giant's Causeway Visitor Centre.

However, Northern Ireland comptroller and auditor general Kieran Donnelly said: "The Signature Projects represent the best way forward for tourism in Northern Ireland and have the potential to achieve international stand-out and increase visitor numbers."

Details: www.niauditoffice.gov.uk

Image: The Titanic Signature Building under construction earlier this year - Ardfern