The Arc is the first residential development at the ambitious scheme in east Belfast which is Europe's largest waterfront development.

The interest in the development was described as "phenomenal" by Mike Smith, chief executive of Titantic Quarter.

Prospective buyers booked appointments online and the successful ones were invited to the marketing suite at Titanic Quarter's new offices in the recently refurbished former Harland & Wolff headquarters.

A website dedicated to The Arc had over 5,000 hits from local home-hunters as well as those in other parts of the UK, the Republic of Ireland, America and Australia - although most of the buyers are from the province.

Mr Smith said: "This represents a huge success for Titanic Quarter. The vast majority of the buyers are Northern Ireland-based which fits well with our vision for The Arc, and indeed the rest of Titanic Quarter, to be a sustainable and vibrant community."

The apartments offer spacious, high spec living accommodation with prices ranging from £195,000 for a one-bedroom apartment to £850,000 for the penthouses.

Mr Thomas O'Doherty, associate at selling agent the Eric Cairns Partnership, said: "Demand for The Arc has been exceptional and we're delighted that we have sold over 350 apartments in such a short period of time. This emphasises the demand for both city centre living and living in a waterfront development."

The Arc is one part of a mixed development which will include restaurants, cafes, public spaces, hotels, leisure facilities and commercial developments.

At 185 acres, Titanic Quarter's scale is unprecedented in Northern Ireland and the entire development has been valued at £1.5bn. It is anticipated that over 20,000 people will live and work in the area.

Meanwhile, the latest Northern Ireland Housing Bulletin from the Department of Social Development has revealed the average selling price of a NHBC-registered new house sold during April-June this year was £214,000 - up £67,000 (45.6%) on the same quarter in 2006.

Prices for apartments also saw a hike of £41,000 (31.3%) to £172,000.

And new house builds are up by only a small percentage - 0.7% - on the previous quarter, with 2,224 NHBC building projects registered.

Other figures showed 4,924 householders presented as homeless to the Housing Executive with 'sharing breakdown or family dispute' being the most common reason given.