The Manchester law firm said it is considering splitting its 95,000 sq ft office requirement between two sites, as it confirmed the start of the next stage of its search.
Pannone, advised by P3 Property Consultants, intends to vacate its current base, in three neighbouring buildings on Deansgate, by spring 2014.
Emma Holt, managing partner, said: "We have spent a great deal of time this year finalising our strategic growth plans to position the firm to capitalise on the opportunities in the evolving legal market. Our planned move to new premises is an integral part of the process.
"We will assess our different needs across the business and will match each need with an appropriate response. This may well lead to a two-site solution in the city centre.
"We are keeping an open mind, however I think there might just be a really innovative property solution out there that will help us achieve our goals."
Peter Gallagher, partner at P3, added: "The property solution is an integral part of the business strategy and we will consider both existing buildings and redevelopment opportunities providing they fulfill the business need. This is an exciting project and if there was a time for a really clever property solution, then this is it."
Pannone employs 620 staff and has offices in Hale, Alderley Edge, London as well as the Deansgate headquarters.