BRASILIA, Oct 26 (Reuters) - Market forecasts for Brazil's 2016 inflation rate rose for a 12th consecutive week and approached the ceiling of the government's target, a central bank survey showed on Monday. The weekly poll of about 100 economists also showed lower forecasts for economic growth in 2015 and 2016, projecting the longest period of economic contraction since the 1930s. Estimates for the central bank's benchmark interest rate at end-2016 also increased. The government targets inflation at 4.5 percent, with a tolerance margin of 2 percentage points. (pct) 2015 2016 previous new previous new forecast forecast forecast forecast Consumer inflation 9.75 9.85 6.12 6.22 Exchange rate 4.00 4.00 4.13 4.20 (reais per U.S dollar, end-period) Interest rate 14.25 14.25 12.75 13.00 (end-period) GDP growth -3.00 -3.02 -1.22 -1.43 Industrial output -7.00 -7.00 -1.00 -1.50 (Reporting by Silvio Cascione; Editing by Kevin Liffey)