The plans, unveiled at Confex today (6 March), will see 2,100sqm of extra conference space added to the venue - which anticipates a £39m annual boost to the local economy.
The project is billed for a completion date of 2016, with work expected to start next year.
Belfast Waterfront Centre communications manager Janice Crowe told C&IT that the corporate market is currently suffering from the recession, but the association market is expected to make up the bulk of bookings.
"We're hoping that the corporate market will pick up in the next few years but there are sectors which are showing positive growth. Facebook and Google have a presence in Ireland, so we will be targeting the likes of them and the emerging IT sector," he added.
The new venue will feature banqueting facilities for 750 delegates, five breakout rooms, each capable of holding 200 delegates.