Cosmological perturbations in singularity-free, deflationary models

We consider scaler perturbations of energy-density for a class of cosmologi cal models where an early phase of accelerated expansion evolves, without a ny fine-tuning for graceful exit, towards the standard Friedman eras of obs erved universe. The quantum-geometric procedure which generates such models agrees with results for string cosmology since it works if dynamics is dom inated by a primordial fluid of extended massive objects. The main result i s that characteristic scales of cosmological interest, connected with the e xtension of such early objects, are selected.