Langtree Group is expecting to submit a planning application in October for 100,000 sq ft of offices at Kingston House in Liverpool city centre.
Martin Mellor, development director of Langtree, said: "We are advancing the plans well with Carey Jones Architects for a 12-storey contemporary design."
The lower floors will contain up to 15,000 sq ft of retail and leisure to complement the commercial uses above.
Subject to planning and the tender process to appoint a contractor Langtree hopes to be on site in the first half of next year with completion late in 2009.
Langtree was appointed preferred developer by Liverpool Vision and the North West Development Agency at the start of this year.
The site of the proposed office scheme, designed by the same architect behind Langtree's Forty Spring Gardens in Manchester city centre, is on the corner of James Street and the Strand. A 1960s office and pub on the plot will be demolished to make way for the new building.
Mellor said the prime waterfront site represented a key commercial opportunity for the city, sitting next to Neptune and Countryside's Mann Island scheme and Grosvenor's Liverpool One.