The new venue will have 8,100sqm of space, sub-divided into three interlinked pillar-free exhibition halls, each 2,700sqm in size.
The hotel, built on the site, is expected to be four or five star, but no operator has been appointed yet. The new facilities will be connected to ACC Liverpool by a sky bridge.
ACC Liverpool chairman David McDonnell said: "The feasibility work we have undertaken demonstrates that this development will be self-funding and will begin to attract millions of pounds of new business to the city as soon as it opens."
Bob Prattey, chief executive of ACC Liverpool, added: "The new venue will enable us to build market share and to attract even larger and more lucrative events, helping to fill the city’s hotels, restaurants and shops with high-spending visitors."
Since opening in 2008, the ACC has held events including the Mobo Awards and is set to host Labour Party’s Annual Conference 2011 in September, which will draw over 10,000 people.