Organisers of one of cycling's flagship professional events are extremely confident ahead of the opening stages in Ireland, a race director said.

The three-day start of the Giro d'Italia in May will pass dramatic Atlantic breakers and the Unesco World Heritage site of the Giant's Causeway. Organisers say up to 140,000 spectators could attend.

Time trials will be held in Belfast, taking in the stately home of the Northern Ireland Parliament at Stormont, before a final leg from the ecclesiastical capital of Armagh to Dublin.

This is the first time the country has hosted an event of this scale attracting such global interest.

Stephen Gallagher, one of the local organisers of the event, said: "For the first time in a generation Ireland probably has the potential to not only win stages but maybe win overall."

More than 200 of the world's elite riders will take part.

Tourist authorities anticipate that the competition, which will include prizes for the top hill climbers and sprinters, will attract thousands of visitors from outside Ireland.

Every other year the start of the Giro, the Grande Partenza, is held outside Italy.

This annual multiple stage race is primarily held in Italy and along with the Tour de France and Vuelta a Espana makes up cycling's prestigious, three week-long Grand Tours. It is considered to be second only to the Tour de France in terms of importance in the cycling world.

The start of the Giro will take place over three days from 9-11 May.

Mr Gallagher, who represents Shadetree Sports which is working with the RCS Italian media company behind the event, said preparatory work was stepping up, with facilities for the cyclists under construction in Belfast.

He said: "This is the first time we have ever done it in Northern Ireland is new to everybody in that respect.

"It gives a fresh perspective on how to do racing like this, how to organise, and has put a huge focus on the race itself.

"RCS are extremely confident and extremely satisfied with the support here locally and being able to work closely with all those government staff has just made it easier."

Special security and public transport arrangements are being put in place. A "bubble" will be put around the riders and their support teams of chefs, medics and managers as they move around the route, entailing extensive road closures.

Riders will be travelling at up to 60 kilometres per hour but much of the route will not be barricaded off so spectators will have an opportunity to get close to their idols.

The competitors will be presented in a special ceremony at Belfast city hall the night before the event.

A series of tourism festivals in Belfast, Armagh and elsewhere are planned to coincide with the race.

Stormont transport minister Danny Kennedy said: "I want us all to seize the opportunity the Giro brings for us to embrace cycling as a viable and safe means of travel.

"Our towns and cities must be designed to create an environment which is inviting people to walk and cycle as much as possible."