The plans will double the Waterfront’s existing conference and exhibition space to attract more international conferences and promote Belfast as a world-class destination for business tourism.
Breaking ground on the new extension, the Lord Mayor of Belfast, Councillor Nichola Mallon, said: "This is a great day for Belfast - for the city, our people, our tourism industry in particular and our economy as a whole. These new facilities will put us on the international map, enabling the Waterfront to attract 50,000 conference delegates each year - twice the current number."
Northern Ireland Tourist Board chairman Howard Hastings added: "The new Belfast Waterfront Conference and Exhibition Centre is set to be another significant step change for tourism in Northern Ireland. Business tourism is currently worth £100 million to the Northern Ireland economy and growing, and business visitors contribute the highest spend per person."
The construction work is scheduled to be completed in December 2015, with the new facilities opening in spring 2016.