The States wants to keep momentum going at Leale's Yard, after buying the majority of the site in the summer.
Leale's Yard has been derelict for years and plans to revitalise it have come and gone.
But as Guernsey's housing crisis continues, developing potentially hundreds of apartments or small homes on the site remains a government priority.
After the last private sector plans fell through, the States bought a large section of Leale's Yard in August.
The head of P&R, deputy Lindsay de Sausmarez, says they want to get the project going and demolish the remaining buildings as soon as possible, and are looking for a firm to carry out the work.
“Leale’s Yard is a strategically important site, so maintaining momentum is essential.
"Development doesn’t take place overnight, especially for a site of this scale, but we’re progressing through the necessary stages as quickly as possible.
"We’re planning the necessary demolition – which will be the first visible signs of progress – at the earliest opportunity.
“Behind the scenes, we’re working hard on plans to improve the transport network in the area - an essential component for this project to succeed."
P&R, as major landowner, says plans will change from those previously drawn up.
But the site will still be a mix of homes and businesses, with the Co-op keeping its section for housing.

Possible job cuts at RBSI in Guernsey and Jersey
Guernsey students beat England's A level pass rate
Guernsey community unites out west for solar eclipse
19 months of traffic lights on busy Guernsey road
New Dean of Guernsey has Alderney connections
Guernsey's youngsters concerned by the high cost of living
A solar eclipse and meteor shower over Guernsey tonight
Average Guernsey home selling for more than £600,000