Mayor Bloomberg was complimented by Titanic Quarter chief executive Mike Smith for fitting Belfast into a packed itinerary which has recently included unveiling a budget for his city of $60bn. Mr Smith said that what Belfast lacked in size, it made up for in ambition.

"Much as I love Belfast we can't match New York in scale and breadth, but we have energy, enterprise and the opportunity at this junction between Europe and North America.

"Citi, Microsoft and GE Healthcare are already on site at the Northern Ireland Science Park, and I believe more will follow."

The launch was attended by Social Development Minister Margaret Ritchie, who said Titanic Quarter was "a symbol of the new Northern Ireland".

"It holds the promise of delivering greater prosperity for our people and a unique investment opportunity for the United States business sector ... the peace dividend is delivering new investment, new hope and offering new opportunities for our people. We have demonstrated that investors can have confidence in Belfast."

UUP Mayor of Belfast Jim Rodgers presented Mr Bloomberg — one of America's richest men and the founder of the eponymous financial news company, which has set up a Belfast bureau — with gifts of linen, crystal and a montage of Titanic images.

Mr Rodgers called the heritage of shipbuidling embodied by the Titanic Quarter as "glorious and proud. Past glories, however, will not create opportunities for our citizens today. This generation must create its own fortunes and its own opportunities, and Titanic Quarter will be at the forefront of that task."

In a good-natured address, Mayor Bloomberg stressed the importance of exchanging the gifts given to him by Mr Rodgers.

"We have no tradition of linen in New York but I have brought you a crystal apple which you have to put on your desk to remind you of the Big Apple," he told his Belfast counterpart.

"In fact, I will check your desk for it the next time."

Mayor Bloomberg jokingly expressed hope of a arrangement of mutual financial aid between Belfast people and New Yorkers.

"There are 8.2m New Yorkers who all told me to say hello from them and for all of you to visit New York and spend lots of money."

Mayor Bloomberg then paid a visit to Hazelwood Integrated College in north Belfast.

The Titanic Quarter visit of Mayor Bloomberg coincided with the submission of plans for 600,000 square feet of offices and financial and professional services, the second phase of the Financial Services Centre.