Winthrop Realty Trust, Boston, says it has paid around $57 million to take over the non-performing $70 million mortgage on 1515 Market St., a 514,000 sq ft office building that counts Pennsylvania state courts, Citizens Bank and Temple among its clients. Statement here.

The building was last purchased for $76 million in 2007, according to city records here.  The buyers were Philadelphia-based Stockton Real Estate Advisors, founded by Rubenstein Co. veterans James Paterno and Christopher Amoroso, backed by national property investor CBRE Realty Finance. More about that deal here.