A city real-estate developer yesterday pleaded guilty to masterminding a $92 million mortgage-fraud scheme.

Thomas Kontogiannis, 61, admitted in Brooklyn federal court that he bought land parcels in Brooklyn and Queens from 2001 to 2003, subdivided the properties, and obtained bogus appraisals to use on loan applications.

Straw buyers then applied for mortgages and took out multiple loans on the same properties, using mortgage and title companies also involved in the scheme, prosecutors said.

Kontogiannis faces more than 30 years behind bars under a plea agreement federal prosecutors.