A process for reducing the viscosity of fracturing fluids in downhole oilfield operations is provided. The process comprises contacting a sulfamate stabilized, bromine-based breaker with an aqueous polysaccharide fracturing fluid, with the breaker present in an amount to reduce the viscosity of the fracturing fluid. A composition which comprises a sulfamate stabilized, bromine-based breaker for use in decreasing the viscosity of an aqueous polysaccharide fracturing fluid for use in subterranean oil and gas wells is also provided.