The landlord who last year bought some of the most run-down buildings in the city, promising to revitalize them, has done just that, but has raised concerns by recently refinancing the properties, taking on an additional $15.5 million in debt. Steve Finkelstein of Finkelstein Timberger Real Estate said that the refinancing he has arranged with Cantor Fitzgerald helps him cover the approximately $10 million in repairs he’s made on the nine Bronx buildings since buying them in April 2011 for about $28 million. Tenant advocates worry that the new debt total of $45.5 million—$10 million more than the mortgage that forced previous owner, Los Angeles-based Milbank Real Estate, into foreclosure—is unsustainable. They are concerned that such a burden will force Scarsdale, N.Y.-based Mr. Finkelstein to skimp on maintenance and repairs. Mr. Finkelstein insists that the problem with the 1920’s-era buildings was never their debt level, but successive owners who failed to take good care of the properties. He made an agreement with tenants to forgive back rent and cap rent increases and he reached a deal with the city to not only correct violations, but to fix the underlying conditions that were causing the infractions.