The struggling Hanover Mall continues to weigh on a $4 billion portfolio of commercial mortgage-backed securities, as Fitch Ratings said it has downgraded a batch of those investment pass-through certificates due to “further deterioration of performance.” The vintage-2005 portfolio was packaged by JPMorgan Chase & Co. at an original value of $4.32 billion. Roughly 8 percent of that balance has since been paid down, leaving a principle balance of $3.98 billion. Fitch said 32 loans within the portfolio have been flagged as “loans of concern.” The Hanover Mall’s outstanding debt of around $8.7 million is the portfolio’s second-largest loan to have transferred to a special servicer. The debt accounts for 2.16 percent of the CMBS portfolio’s entire balance.