Plans for the development of a new £18.5m visitor centre at the Giant's Causeway, Northern Ireland, have received a £9.25m boost from the Northern Ireland Tourist Board (NITB).

The funding announcement comes after the tourism agency reached an agreement with the National Trust (NT), which owns the attraction and plans to enhance the World Heritage Site's visitor experience.

Dublin-based architects heneghan.peng are behind the designs for the new visitor centre, which has also received a £3m grant from the Heritage Lottery Fund (HLF) and £4m from the NT.

A fundraising campaign to secure the remaining £2m needed for the scheme is already underway, while construction work is expected to start on the main build in autumn 2010.

Preliminary work is due to start in May to create new car parks, the relocation of retail and tourist information to the Causeway Hotel and the provision of additional catering kiosks and toilet facilities.

Design group Event Communications has been selected to develop the interpretative aspect of the visitor centre, which is set to open in summer 2012 and will also see an improved trail and path network.

NITB chief executive Alan Clarke said: "The Giant's Causeway is the jewel in the crown of NITB's Causeway Coast and Glens Signature Project. NITB funding of £9.25m, and 50 per cent of total project cost of £18.5m, will allow the building of the new visitor facilities to commence very shortly."

NT director for Northern Ireland Hilary McGrady added: "It is just two short years since the National Trust took the lead in this project and we are now literally weeks away from breaking ground."